Light emitting device comprising a lightguide with a glass core layer

ABSTRACT

In one aspect, a light emitting device comprises a lightguide formed from a film with a glass core layer and a thickness less than 0.5 millimeters, a plurality of strips extending from a lightguide region forming a light input surface, a light emitting region, and a light source positioned to emit light into the light input surface. In one embodiment, the light emitting device comprises a cladding layer optically coupled to the glass core layer. In one embodiment, a largest dimension of the light emitting region in a plane comprising the light emitting region divided by an average thickness of the glass core layer in the light emitting region is greater than 500. The light source may comprise a peak wavelength between 350 nanometers and 400 nanometers or between 800 nanometers and 1200 nanometers. The glass core layer may be a borosilicate glass.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/376,797 filed Apr. 5, 2019, entitled “Light emitting device with ahigh luminous flux density in a film-based lightguide,” which is acontinuation of U.S. application Ser. No. 16/049,397 filed Jul. 30,2018, entitled “Film-based light fixture for illumination beneath aceiling tile,” which is a continuation of U.S. application Ser. No.15/790,721 filed Oct. 23, 2017, entitled “Film-based light fixture withlight reflecting layer and fastener” which is a continuation of U.S.application Ser. No. 15/478,005 filed Apr. 3, 2017, entitled “Film-basedlight fixture with see-through light emitting region,” now U.S. Pat. No.9,645,304, which is a continuation of U.S. application Ser. No.14/003,569 filed Nov. 11, 2013 entitled “Directional front illuminatingdevice comprising a film based lightguide with high optical clarity inthe light emitting region,” now U.S. Pat. No. 9,645,304, which was theNational Stage of International Application No. PCT/US2012/028578 filedMar. 9, 2012, entitled “Light Emitting Device with Adjustable LightOutput Profile,” which claims the benefit of U.S. ProvisionalApplication No. 61/450,711 filed Mar. 9, 2011, entitled “IlluminationDevice Comprising a Film-based Lightguide,” the entire contents of eachare incorporated herein by reference.

TECHNICAL FIELD

The subject matter disclosed herein generally relates to light emittingdevices such as light fixtures, backlights, frontlights, light emittingsigns, passive displays, and active displays and their components andmethods of manufacture. Light emitting devices are needed which arethinner, lighter weight, cheaper to manufacture, and scalable to largesizes.

BACKGROUND

Conventionally, in order to reduce the thickness of displays, lightfixtures, and backlights, edge-lit configurations using rigidlightguides have been used to receive light from the edge and directlight out of a larger area face. These types of light emitting devicesare typically housed in relatively thick, rigid frames that do not allowfor component or device flexibility and require long lead times fordesign changes. The volume of these devices remains large and oftenincludes thick or large frames or bezels around the device. The thicklightguides (typically 2 millimeters (mm) and larger) limit the designconfigurations, production methods, and illumination modes.

The ability to further reduce the thickness and overall volume of thesearea light emitting devices has been limited by the ability to couplesufficient light flux into a thinner lightguide. Typical light emittingdiode (LED) light sources have a light emitting area dimension of atleast 1 mm, and there is often difficulty controlling the lightentering, propagating through, and coupled out of the 2 mm lightguide tomeet design requirements. The displays incorporating the 2 mmlightguides are typically limited to small displays such as displayswith a 33 centimeters (cm) diagonal measurement or less. Many systemsizes are thick due to designs that use large light sources and largeinput coupling optics or methods. Some systems using one lightguide perpixel (such as fiber optic based systems) require a large volume andhave low alignment tolerances. In production, thin lightguides have beenlimited to coatings on rigid wafers for integrated optical components.

SUMMARY

In one aspect, a light emitting device comprises a lightguide formedfrom a film with a glass core layer and a thickness less than 0.5millimeters, a plurality of strips extending from a lightguide regionforming a light input surface, a light emitting region, and a lightsource positioned to emit light into the light input surface. In oneembodiment, the light emitting device comprises a cladding layeroptically coupled to the glass core layer. In one embodiment, a largestdimension of the light emitting region in a plane comprising the lightemitting region divided by an average thickness of the glass core layerin the light emitting region is greater than 500. The light source maycomprise a peak wavelength between 350 nanometers and 400 nanometers orbetween 800 nanometers and 1200 nanometers. The glass core layer may bea borosilicate glass.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of one embodiment of a light emitting deviceincluding a light input coupler disposed on one side of a lightguide.

FIG. 2 is a perspective view of one embodiment of a light input couplerwith coupling lightguides folded in the −y direction.

FIG. 3 is a top view of one embodiment of a light emitting device withthree light input couplers on one side of a lightguide.

FIG. 4 is a top view of one embodiment of a light emitting device withtwo light input couplers disposed on opposite sides of a lightguide.

FIG. 5 is a top view of one embodiment of a light emitting device withtwo light input couplers disposed on the same side of a lightguidewherein the optical axes of the light sources are oriented substantiallytoward each other.

FIG. 6 is a cross-sectional side view of one embodiment of a lightemitting device with a substantially flat light input surface comprisedof flat edges of a coupling lightguide disposed to receive light from alight source.

FIG. 7 is a cross-sectional view of one embodiment of a light emittingdevice including a film-based lightguide, two light input couplers, anda low-contact area cover extending substantially around the two lightinput couplers and the film-based lightguide in at least one plane.

FIG. 8 is a perspective view of one embodiment of a light emittingdevice disposed adjacent a wall.

FIG. 9 is a cross-sectional side view of a light emitting deviceincluding a lightguide with a core region, two cladding regions, and aplastically deformable material.

FIG. 10 is a cross-sectional side view of a portion of a light emittingdevice including a lightguide with a core region, two cladding regions,and a plastically deformable light reflecting film.

FIG. 11 is a cross-sectional side view of a portion of a light emittingdevice including a lightguide with a core region disposed between a lowrefractive index cladding region and an air-gap cladding regionincluding light transmitting adhesive.

FIG. 12 is a perspective view of a light emitting device including afilm-based lightguide formed into a wave-like shape.

FIG. 13 is a photometric plot of an angular luminous intensity output ofthe light emitting device of FIG. 12.

FIG. 14 is a perspective view of a light emitting device including afilm-based lightguide formed into a wave-like shape, a first light inputcoupler, and a second light input coupler.

FIG. 15 is a perspective view of a light emitting device including afilm-based lightguide formed into a wave-like shape, bendable sidesupport rails, a first light input coupler, and a second light inputcoupler.

FIG. 16 is a perspective view of a light emitting device including afilm-based lightguide formed into a wave-like shape, a plasticallydeformable mesh support physically coupled to the film-based lightguide,and a light input coupler.

FIG. 17 is a perspective view of a light emitting device including afilm-based lightguide formed into a wave-like shape, a first set ofplastically deformable wire supports, and a second set of plasticallydeformable wire supports oriented orthogonal to the first set ofplastically deformable wire supports with a pitch of the two setsdiffering.

FIG. 18 is a perspective view of one embodiment of a light emittingdevice including a cladding layer peeled back.

FIG. 19 is a perspective view of the embodiment shown in FIG. 18 as thecladding layer is re-applied.

FIG. 20 is a bottom view of one embodiment of a light emitting devicedisposed in a support surface or structure, such as a ceiling, whereinthe light input coupler is within the ceiling and the lightguide extendsacross the ceiling.

FIG. 21 is a cross-sectional side view of one embodiment of a lightemitting device disposed underneath a ceiling tile.

FIG. 22 is a perspective view of one embodiment of a light emittingdevice including a film-based lightguide curved in an arcuate shape inthe +z direction between two light input couplers that are separated byan adjustable extension guide.

FIG. 23 is a perspective view the light emitting device of FIG. 22wherein the adjustable extension guide has been extended such that thelight input couplers are separated by a larger distance.

FIG. 24 is a perspective view the light emitting device of FIG. 22wherein the adjustable extension guide has been extended and a filmcurvature has been flipped such that the arc extends in the −zdirection.

FIG. 25 is a perspective view of one embodiment of a light emittingdevice including a film-based lightguide formed into a wave-like shapebetween two light input couplers that are separated by an adjustableextension guide.

FIG. 26 is a perspective view of one embodiment of a light emittingdevice including a film-based lightguide formed into a wave-like shapewith light emitting regions oriented in an average first direction froma reference direction.

FIG. 27 is a perspective view of one embodiment of the light emittingdevice of FIG. 26 wherein a spacing between pairs of lightguidepositioning rods has been increased.

FIG. 28 is a perspective view of one embodiment of a light emittingdevice including light input couplers and a film-based lightguide withadjustable tension rails.

FIG. 29 is a perspective view of one embodiment of a light emittingdevice including light input couplers and a film-based lightguide withadjustable tension rails physically coupled to lightguide positioningrods with light output from both sides of the film based lightguide.

FIG. 30 is a perspective view of one embodiment of a light emittingdevice including light input couplers and the film-based lightguide withflexible adjustment rods extending through holes in the film basedlightguide.

FIG. 31 is a perspective view of one embodiment of an elongated lightemitting device including a light input coupler and a film-basedlightguide with a lightguide film adjustment mechanism.

FIG. 32 is a perspective view of the light emitting device of FIG. 31with drawstrings pulled such that a middle region of the film-basedlightguide is pulled closer to the light input coupler.

FIG. 33 is a top view of one embodiment of a light emitting including alight input coupler, a film-based lightguide, and a light output couplerincluding coupling lightguides.

FIG. 34 is a perspective view of one embodiment of a light emittingdevice with a longer dimension in the y direction than the x directionincluding two sets of coupling lightguides on opposite sides of afilm-based lightguide that are folded under and stacked adjacent eachother.

FIG. 35 is a perspective view of one embodiment of an elongated lightemitting device including a light input coupler and a film-basedlightguide with two lightguide positioning rods.

FIG. 36 is a perspective view of the light emitting device of FIG. 35wherein relative positions of the lightguide positioning rods have beenchanged.

FIG. 37 is a side view of one embodiment of a light emitting deviceincluding a film-based lightguide formed into a bulbous shape withcoupling lightguides twisted and stacked together.

FIG. 38 is a top view of one embodiment of a light emitting deviceincluding a light input coupler and output coupling lightguides disposedto recycle light back to input coupling lightguides.

FIG. 39 is a perspective view of one embodiment of a light emittingdevice including a light input coupler and a film-based lightguidehanging downward such that a substantially vertical region of thefilm-based lightguide includes a light emitting region that emits light.

FIG. 40 is a perspective view of one embodiment of a light emittingdevice including a light input coupler that couples light into afilm-based distribution lightguide.

FIG. 41 is a side view of one embodiment of a light emitting deviceincluding a light input coupler which couples light into a film-baseddistribution lightguide.

FIG. 42 is a perspective view of one embodiment of a light emittingdevice including a light source disposed to couple light into an arrayof lightguide strips including light emitting regions.

FIG. 43 is a perspective view of one embodiment of a light emittingdevice including a light input coupler and a lightguide with atubular-shaped region.

FIG. 44 is a perspective view of one embodiment of a light emittingdevice including a light input coupler and a flexible, reconfigurablefilm-based lightguide.

FIG. 45 is a perspective view of the light emitting device of FIG. 44wherein the reconfigurable film-based lightguide is folded into a shapewith a wave-like cross-sectional profile in the y-z plane.

FIG. 46 is a cross-sectional side view of one embodiment of a lightemitting device including two sets of coupling lightguides on oppositesides of a film-based lightguide that are folded underneath thefilm-based lightguide and stacked adjacent each other.

FIG. 47 is a cross-sectional side view of one embodiment of a lightemitting device including a film-based lightguide in the shape of a domewith a camera disposed within the dome.

FIG. 48 is a perspective view of one embodiment of a light emittingdevice including a film-based lightguide wherein substantially all ofthe light is emitted with a directional component in the +y direction.

FIG. 49 is a cross-sectional side view of one embodiment of anincandescent light bulb replacement light emitting device including afilm-based lightguide in the shape of a dome with a protective bulbsurrounding the film-based lightguide.

FIG. 50 is a cross-sectional side view of one embodiment of a lightemitting device including a film-based lightguide with a substantiallyflat light emitting surface with a protective cover surrounding thefilm-based lightguide.

FIG. 51 is a perspective view of one embodiment of a self-illuminatedpicture frame light emitting device including a light source andcoupling lightguides within a frame.

FIG. 52 is a perspective view of one embodiment of a light emittingdevice including light input couplers and rotatable film-basedlightguides physically coupled to rigid, bendable substrates.

FIG. 53 is a perspective view of a light emitting device including alight input coupler, a film-based lightguide, and a sensor disposed toreceive communication or visual information from an electronic device ora person.

FIG. 54 is a perspective view of a light emitting point of purchasedisplay including a light input coupler, and a film-based lightguideextending into a base of the point of purchase display.

FIG. 55 is a perspective view of a light emitting device functioning asa ubiquitous display including a light input coupler, a film-basedlightguide, and a sensor disposed to receive communication, such radiofrequency communication from an electronic device, a wirelessthermometer, or a personal health monitor.

FIG. 56 is a perspective view of a light emitting device incorporatedinto flexible packaging including a light input coupler and a film-basedlightguide.

DETAILED DESCRIPTION

The features and other details of several embodiments will now be moreparticularly described. It will be understood that particularembodiments described herein are shown by way of illustration and not aslimitations. The principal features can be employed in variousembodiments without departing from the scope of any particularembodiment. All parts and percentages are by weight unless otherwisespecified.

Definitions

“Electroluminescent sign” is defined herein as a means for displayinginformation wherein the legend, message, image or indicia thereon isformed by or made more apparent by an electrically excitable source ofillumination. This includes illuminated cards, transparencies, pictures,printed graphics, fluorescent signs, neon signs, channel letter signs,light box signs, bus-stop signs, illuminated advertising signs, EL(electroluminescent) signs, LED signs, edge-lit signs, advertisingdisplays, liquid crystal displays, electrophoretic displays, point ofpurchase displays, directional signs, illuminated pictures, and otherinformation display signs. Electroluminescent signs can be self-luminous(emissive), back-illuminated (back-lit), front illuminated (front-lit),edge-illuminated (edge-lit), waveguide-illuminated or otherconfigurations wherein light from a light source is directed throughstatic or dynamic means for creating images or indicia.

“Optically coupled” as defined herein refers to coupling of two or moreregions or layers such that the luminance of light passing from oneregion to the other is not substantially reduced by Fresnel interfacialreflection losses due to differences in refractive indices between theregions. “Optical coupling” methods include methods of coupling whereinthe two regions coupled together have similar refractive indices orusing an optical adhesive with a refractive index substantially near orbetween the refractive index of the regions or layers. Examples of“optical coupling” include, without limitation, lamination using anindex-matched optical adhesive, coating a region or layer onto anotherregion or layer, or hot lamination using applied pressure to join two ormore layers or regions that have substantially close refractive indices.Thermal transferring is another method that can be used to opticallycouple two regions of material. Forming, altering, printing, or applyinga material on the surface of another material are other examples ofoptically coupling two materials. “Optically coupled” also includesforming, adding, or removing regions, features, or materials of a firstrefractive index within a volume of a material of a second refractiveindex such that light propagates from the first material to the secondmaterial. For example, a white light scattering ink (such as titaniumdioxide in a methacrylate, vinyl, or polyurethane based binder) may beoptically coupled to a surface of a polycarbonate or silicone film byinkjet printing the ink onto the surface. Similarly, a light scatteringmaterial such as titanium dioxide in a solvent applied to a surface mayallow the light scattering material to penetrate or adhere in closephysical contact with the surface of a polycarbonate or silicone filmsuch that it is optically coupled to the film surface or volume.

“Lightguide” or “waveguide” refers to a region bounded by the conditionthat light rays propagating at an angle that is larger than the criticalangle will reflect and remain within the region. In a lightguide, thelight will reflect or TIR (totally internally reflect) if it the angle(a) satisfies the condition α>sin⁻¹(n₂/n₁), where n₁ is the refractiveindex of the medium inside the lightguide and n₂ is the refractive indexof the medium outside the lightguide. Typically, n₂ is air with arefractive index of n≈1; however, high and low refractive indexmaterials can be used to achieve lightguide regions. A lightguide doesnot need to be optically coupled to all of its components to beconsidered as a lightguide. Light may enter from any face (orinterfacial refractive index boundary) of the waveguide region and maytotally internally reflect from the same or another refractive indexinterfacial boundary. A region can be functional as a waveguide orlightguide for purposes illustrated herein as long as the thickness islarger than the wavelength of light of interest. For example, alightguide may be a 5 micron region or layer of a film or it may be a 3millimeter sheet comprising a light transmitting polymer.

“In contact” and “disposed on” are used generally to describe that twoitems are adjacent one another such that the whole item can function asdesired. This may mean that additional materials can be present betweenthe adjacent items, as long as the item can function as desired.

A “film” as used herein refers to a thin region, membrane, or layer ofmaterial.

A “bend” as used herein refers to a deformation or transformation inshape by the movement of a first region of an element relative to asecond region, for example. Examples of bends include the bending of aclothes rod when heavy clothes are hung on the rod or rolling up a paperdocument to fit it into a cylindrical mailing tube. A “fold” as usedherein is a type of bend and refers to the bend or lay of one region ofan element onto a second region such that the first region covers atleast a portion of the second region. An example of a fold includesbending a letter and forming creases to place it in an envelope. A folddoes not require that all regions of the element overlap. A bend or foldmay be a change in the direction along a first direction along a surfaceof the object. A fold or bend may or may not have creases and the bendor fold may occur in one or more directions or planes such as 90 degreesor 45 degrees. A bend or fold may be lateral, vertical, torsional, or acombination thereof. In relation to the present invention the term“micron” is used as a shorthand reference to the SI unit micrometres.

In one embodiment, a device includes a film-based lightguide and a filmadjustment mechanism configurable to adjust an orientation of a regionof the film-based lightguide such that an angular light output profilefrom the device changes when a light source emits light that travels ina waveguide condition through the film-based lightguide.

In another embodiment, a light emitting device has an adjustable angularlight output profile wherein a first radius of curvature of a lightemitting region is adjustable to a second radius of curvature to changean angular light output profile of light emitted from the light emittingdevice.

In another embodiment, a method of changing an angular light outputprofile of a light emitting device includes changing an orientation of alight emitting region of a film-based lightguide configured to receivelight emitted from a light source through an array of couplinglightguides. In one embodiment, changing an orientation of the lightemitting region includes changing a radius of curvature of the lightemitting region. In one embodiment, changing an orientation of the lightemitting region includes adjusting a film adjustment mechanismphysically coupled to the film-based lightguide.

In one embodiment, the orientation of a region of the film-basedlightguide is adjustable to change an angle of a peak luminous intensityor an angular full-width at half maximum luminous intensity of theangular light output profile from the light emitting device in a lightoutput plane. In one embodiment, the light emitting region of the filmbased lightguide is adjusted to change the angular light output profile.In a further embodiment, the light emitting device further includes afilm adjustment mechanism configurable to adjust the first radius ofcurvature of the light emitting region. In one embodiment, the filmadjustment mechanism is electronically adjustable.

In another embodiment, a light emitting device includes an adhesivelayer operatively coupled to a film-based lightguide that can support aweight of the film-based lightguide or light emitting device. In anotherembodiment, a light emitting device includes one or more removableand/or replaceable light extraction patterns or films includingpatterns. In a further embodiment, a light emitting device emits lighttoward substantially only a first side of the film and a camera orviewer disposed on an opposing second side receives light entering fromthe first side passing through the film. In one embodiment, the filmprovides privacy or security by not permitting a viewer to readily seethrough a light emitting film.

Light Emitting Device

In one embodiment, a light emitting device includes a first lightsource, a light input coupler, a light mixing region, and a lightguideincluding a light emitting region with a light extraction feature. Inone embodiment, the first light source has a first light source emittingsurface, the light input coupler includes an input surface disposed toreceive light from the first light source and transmit the light throughthe light input coupler by total internal reflection through a pluralityof coupling lightguides. In this embodiment, light exiting the couplinglightguides is re-combined and mixed in a light mixing region anddirected through total internal reflection within a lightguide orlightguide region. Within the lightguide, a portion of incident light isdirected within the light extracting region by light extracting featuresinto a condition whereupon the angle of light is less than the criticalangle for the lightguide and the directed light exits the lightguidethrough the lightguide light emitting surface.

In a further embodiment, the lightguide is a film with light extractingfeatures below a light emitting device output surface within the film.The film is separated into coupling lightguide strips which are foldedsuch that the coupling lightguide strips form a light input coupler witha first input surface formed by the collection of edges of the couplinglightguide strips.

In one embodiment, the light emitting device has an optical axis definedherein as the direction of peak luminous intensity for light emittingfrom the light emitting surface or region of the device for devices withoutput profiles with one peak. For optical output profiles with morethan one peak and the output is symmetrical about an axis, such as witha “batwing” type profile, the optical axis of the light emitting deviceis the axis of symmetry of the light output. In light emitting deviceswith angular luminous intensity optical output profiles with more thanone peak which are not symmetrical about an axis, the light emittingdevice optical axis is the angular weighted average of the luminousintensity output. For non-planar output surfaces, the light emittingdevice optical axis is evaluated in two orthogonal output planes and maybe a constant direction in a first output plane and at a varying anglein a second output plane orthogonal to the first output plane. Forexample, light emitting from a cylindrical light emitting surface mayhave a peak angular luminous intensity (thus light emitting deviceoptical axis) in a light output plane that does not include the curvedoutput surface profile and the angle of luminous intensity could besubstantially constant about a rotational axis around the cylindricalsurface in an output plane including the curved surface profile. Thus,the peak angular intensity is a range of angles. When the light emittingdevice has a light emitting device optical axis in a range of angles,the optical axis of the light emitting device comprises the range ofangles or an angle chosen within the range. The optical axis of a lensor element is the direction of which there is some degree of rotationalsymmetry in at least one plane and as used herein corresponds to themechanical axis. The optical axis of the region, surface, area, orcollection of lenses or elements may differ from the optical axis of thelens or element, and as used herein is dependent on the incident lightangular and spatial profile, such as in the case of off-axisillumination of a lens or element.

Light Input Coupler

In one embodiment, a light input coupler includes a plurality ofcoupling lightguides disposed to receive light emitting from a lightsource and channel the light into a lightguide. In one embodiment, theplurality of coupling lightguides are strips cut from a lightguide filmsuch that each coupling lightguide strip remains un-cut on at least oneedge but can be rotated or positioned (or translated) substantiallyindependently from the lightguide to couple light through at least oneedge or surface of the strip. In another embodiment, the plurality ofcoupling lightguides are not cut from the lightguide film and areseparately optically coupled to the light source and the lightguide. Inanother embodiment, the light emitting device includes a light inputcoupler having a core region of a core material and a cladding region orcladding layer of a cladding material on at least one face or edge ofthe core material with a refractive index less than a refractive indexof the core material. In other embodiment, the light input couplerincludes a plurality of coupling lightguides wherein a portion of lightfrom a light source incident on a face of at least one strip is directedinto the lightguide such that light travels in a waveguide condition.The light input coupler may also include one or more of the following: astrip folding device, a strip holding element, and an input surfaceoptical element.

Light Source

In one embodiment, a light emitting device includes at least one lightsource including one or more of the following: a fluorescent lamp, acylindrical cold-cathode fluorescent lamp, a flat fluorescent lamp, alight emitting diode, an organic light emitting diode, a field emissivelamp, a gas discharge lamp, a neon lamp, a filament lamp, incandescentlamp, an electroluminescent lamp, a radiofluorescent lamp, a halogenlamp, an incandescent lamp, a mercury vapor lamp, a sodium vapor lamp, ahigh pressure sodium lamp, a metal halide lamp, a tungsten lamp, acarbon arc lamp, an electroluminescent lamp, a laser, a photonic bandgapbased light source, a quantum dot based light source, a high efficiencyplasma light source, and a microplasma lamp. The light emitting devicemay include a plurality of light sources arranged in an array, onopposite sides of a lightguide, on orthogonal sides of a lightguide, on3 or more sides of a lightguide, or on 4 sides of a substantially planerlightguide. The array of light sources may be a linear array of discreteLED packages including at least one LED die. In another embodiment, alight emitting device includes a plurality of light sources within onepackage disposed to emit light toward a light input surface. In oneembodiment, the light emitting device includes any suitable number oflight sources, such as 1, 2, 3, 4, 5, 6, 8, 9, 10, or more than 10 lightsources. In another embodiment, the light emitting device includes anorganic light emitting diode disposed to emit light as a light emittingfilm or sheet. In another embodiment, the light emitting device includesan organic light emitting diode disposed to emit light into alightguide.

In one embodiment, a light emitting device includes at least onebroadband light source that emits light in a wavelength spectrum largerthan 100 nanometers. In another embodiment, a light emitting deviceincludes at least one narrowband light source that emits light in anarrow bandwidth less than 100 nanometers. In another embodiment, alight emitting device comprises at least one broadband light source thatemits light in a wavelength spectrum larger than 100 nanometers or atleast one narrowband light source that emits light in a narrow bandwidthless than 100 nanometers. In one embodiment a light emitting devicecomprises at least one narrowband light source with a peak wavelengthwithin a range selected from the group of 300 nm-350 nm, 350 nm-400 nm,400 nm-450 nm, 450 nm-500 nm, 500 nm-550 nm, 550 nm-600 nm, 600 nm-650nm, 650 nm-700 nm, 700 nm-750 nm, 750 nm-800 nm, and 800 nm-1200 nm. Thelight sources may be chosen to match the spectral qualities of red,green and blue such that collectively when used in a light emittingdevice used as a display, the color gamut area is at least one selectedfrom the group of 70% NTSC, 80% NTSC, 90% NTSC, 100% NTSC, and 60%, 70%,80%, 90%, and 95% of the visible CIE u′ v′ color gamut of a standardviewer. In one embodiment, at least one light source is a white LEDpackage including a red LED, a green LED, and a blue LED.

In another embodiment, at least two light sources with different colorsare disposed to couple light into the lightguide through at least onelight input coupler. The light source may also include a photonicbandgap structure, a nano-structure or another suitablethree-dimensional arrangement that provides light output with an angularFWHM less than one selected from the group of: 120 degrees, 100 degrees,80 degrees, 60 degrees, 40 degrees, and 20 degrees.

In another embodiment, a light emitting device includes a light sourceemitting light in an angular full-width at half maximum intensity ofless than one selected from 150 degrees, 120 degrees, 100 degrees, 80degrees, 70 degrees, 60 degrees, 50 degrees, 40 degrees, 30 degrees, 20degrees, and 10 degrees in one or more output planes. In anotherembodiment, the light source further includes one or more of thefollowing: a primary optic, a secondary optic, and a photonic bandgapregion, and the angular full-width at half maximum intensity of thelight source is less than one selected from 150 degrees, 120 degrees,100 degrees, 80 degrees, 70 degrees, 60 degrees, 50 degrees, 40 degrees,30 degrees, 20 degrees, and 10 degrees.

Color Tuning

In one embodiment, the light emitting device includes two or more lightsources and the relative output of the two light sources is adjusted toachieve a desired color in a light emitting region of the lightguide oran area of light output on the light emitting device includes aplurality of lightguides overlapping in the region. For example, in oneembodiment, the light emitting device includes a red LED, a green LED,and a blue LED disposed to couple light into the light input surface ofa stack of coupling lightguides. The light mixes within the lightguideand is output in a light emitting region of the lightguide. By turningon the red LED and the blue LED, for example, a purple colored lightemitting region is achieved. In another embodiment, the relative lightoutput of the light sources is adjusted to compensate for thenon-uniform spectral absorption in an optical element of the lightemitting device. For example, in one embodiment, the output of the blueLED in milliwatts is increased to a level more than the red output inmilliwatts in order to compensate for more blue light absorption in alightguide (or blue light scattering) such that the light emittingregion has a substantially white light output in a particular region.

Wavelength Conversion Material

In another embodiment, the light source emits blue and/or ultravioletlight and is combined with a phosphor. In another embodiment, a lightemitting device includes a light source with a first activating energyand a wavelength conversion material which converts a first portion ofthe first activating energy into a second wavelength different than thefirst wavelength. In another embodiment, the light emitting deviceincludes at least one wavelength conversion material selected from thegroup of: fluorophore, phosphor, fluorescent dye, inorganic phosphor,photonic bandgap material, quantum dot material, fluorescent protein,fusion protein, fluorophores attached to protein to specific functionalgroups (such as amino groups (active ester, carboxylate, isothiocyanate,hydrazine), carboxyl groups (carbodiimide), thiol (maleimide, acetylbromide), azide (via click chemistry or non-specifically(glutaraldehyde))), quantum dot fluorophore, small moleculefluorophores, aromatic fluorophores, conjugated fluorophores,fluorescent dye and other wavelength conversion material.

LED Array

In one embodiment, the light emitting device includes a plurality ofLEDs or LED packages wherein the plurality of LEDs or LED packagesincludes an array of LEDs. In another embodiment, the input array ofLEDs can be arranged to compensate for uneven absorption of lightthrough longer versus shorter lightguides. In another embodiment, theabsorption is compensated for by directing more light into the lightinput coupler corresponding to the longer coupling lightguides or longerlightguides.

Light Input Coupler Input Surface

In one embodiment, the light input coupler includes a collection ofcoupling lightguides with a plurality of edges forming a light couplerinput surface. In another embodiment, an optical element is disposedbetween the light source and at least one coupling lightguide whereinthe optical element receives light from the light source through a lightcoupler input surface. In some embodiments, the input surface issubstantially polished, flat, or optically smooth such that light doesnot scatter forwards or backwards from pits, protrusions or other roughsurface features. In some embodiments, an optical element is disposed tobetween the light source and at least one coupling lightguide to providelight redirection as an input surface (when optically coupled to atleast one coupling lightguide) or as an optical element separate oroptically coupled to at least one coupling lightguide such that morelight is redirected into the lightguide at angles greater than thecritical angle within the lightguide than would be the case without theoptical element or with a flat input surface. The coupling lightguidesmay be grouped together such that the edges opposite the lightguideregion are brought together to form an input surface including theirthin edges.

Light Collimating Optical Element

In one embodiment, the light input coupler includes a light collimatingoptical element. A light collimating optical element receives light fromthe light source with a first angular full-width at half maximumintensity within at least one input plane and redirects a portion of theincident light from the light source such that the angular full-width athalf maximum intensity of the light is reduced in the first input plane.In one embodiment, the light collimating optical element is one or moreof the following: a light source primary optic, a light source secondaryoptic, a light input surface, and an optical element disposed betweenthe light source and at least one coupling lightguide. In anotherembodiment, the light collimating element is one or more of thefollowing: an injection molded optical lens, a thermoformed opticallens, and a cross-linked lens made from a mold. In another embodiment,the light collimating element reduces the angular full-width at halfmaximum (FWHM) intensity within the input plane and a plane orthogonalto the input plane.

Coupling Light Guide

In one embodiment, the coupling lightguide is a region wherein lightwithin the region can travel in a waveguide condition and a portion ofthe light input into a surface or region of the coupling lightguidespasses through the coupling lightguide toward a lightguide or lightmixing region. The coupling lightguide, in some embodiments, may serveto geometrically transform a portion of the flux from a light sourcefrom a first shaped area to a second shaped area different from thefirst shaped area. In an example of this embodiment, the light inputsurface of the light input coupler formed from the edges of foldedstrips (coupling lightguides) of a planar film has dimensions of arectangle that is 3 millimeters by 2.7 millimeters and the light inputcoupler couples light into a planar section of a film in the lightmixing region with a cross-sectional dimensions of 40.5 millimeters by0.2 millimeters.

Coupling Lightguide Folds and Bends

In one embodiment, a light emitting device includes a light mixingregion disposed between a lightguide and strips or segments cut to formcoupling lightguides, whereby a collection of edges of the strips orsegments are brought together to form a light input surface of the lightinput coupler disposed to receive light from a light source. In oneembodiment, the light input coupler includes a coupling lightguidewherein the coupling lightguide includes at least one fold or bend in aplane such that at least one edge overlaps another edge. In anotherembodiment, the coupling lightguide includes a plurality of folds orbends wherein edges of the coupling lightguide can be abutted togetherin region such that the region forms a light input surface of the lightinput coupler of the light emitting device. In one embodiment, at leastone coupling lightguide includes a strip or a segment that is bent orfolded to radius of curvature of less than 75 times a thickness of thestrip or the segment. In another embodiment, at least one couplinglightguide includes a strip or a segment that is bended or folded toradius of curvature greater than 10 times a thickness of the strip orthe segment. In another embodiment, at least one coupling lightguide isbent or folded such that a longest dimension in a cross-section throughthe light emitting device or coupling lightguide in at least one planeis less than without the fold or bend. Segments or strips may be bent orfolded in more than one direction or region and the directions offolding or bending may be different between strips or segments.

Stacked Strips or Segments of Film Forming a Light Input Coupler

In one embodiment, the light input coupler is region of a film thatcomprises the lightguide and the light input coupler which comprisesstrip sections of the film which form coupling lightguides that aregrouped together to form a light coupler input surface. The couplinglightguides may be grouped together such the edges opposite thelightguide region are brought together to form an input surfacecomprising of their thin edges. A planar input surface for a light inputcoupler can provide beneficial refraction to redirect a portion of theinput light from the surface into angles such that it travels at anglesgreater than the critical angle for the lightguide. In anotherembodiment, a substantially planar light transmitting element isoptically coupled to the grouped edges of coupling lightguides. One ormore of the edges of the coupling lightguides may be polished, melted,adhered with an optical adhesive, solvent welded, or otherwise opticallycoupled along a region of the edge surface such that the surface issubstantially polished, smooth, flat, or substantially planarized. Thispolishing can aide to reduce light scattering, reflecting, or refractioninto angles less than the critical angle within the coupling lightguidesor backwards toward the light source. The light input surface maycomprise a surface of the optical element, the surface of an adhesive,the surface of more than one optical element, the surface of the edge ofone or more coupling lightguides, or a combination of one or more of theaforementioned surfaces. The light input coupler may also comprise anoptical element that has an opening or window wherein a portion of lightfrom a light source may directly pass into the coupling lightguideswithout passing through the optical element. The light input coupler oran element or region therein may also comprise a cladding material orregion.

In another embodiment, the cladding layer is formed in a materialwherein under at least one selected from the group of heat, pressure,solvent, and electromagnetic radiation, a portion of the cladding layermay be removed. In one embodiment, the cladding layer has a glasstransition temperature less than the core region and pressure applied tothe coupling lightguides near the light input edges reduces the totalthickness of the cladding to less than one selected from the group of10%, 20%, 40%, 60%, 80% and 90% of the thickness of the cladding regionsbefore the pressure is applied. In another embodiment, the claddinglayer has a glass transition temperature less than the core region andheat and pressure applied to the coupling lightguides near the lightinput edges reduces the total thickness of the cladding regions to lessthan one selected from the group of 10%, 20%, 40%, 60%, 80% and 90% ofthe thickness of the cladding regions before the heat and pressure isapplied. In another embodiment, a pressure sensitive adhesives functionsas a cladding layer and the coupling lightguides are folded such thatthe pressure sensitive adhesive or component on one or both sides of thecoupling lightguides holds the coupling lightguides together and atleast 10% of the thickness of the pressure sensitive adhesive is removedfrom the light input surface by applying heat and pressure.

Light Mixing Region

In one embodiment, a light emitting device includes a light mixingregion disposed in an optical path between the light input coupler andthe lightguide region. The light mixing region can provide a region forthe light output from individual coupling lightguides to mix togetherand improve at least one of a spatial luminance uniformity, a spatialcolor uniformity, an angular color uniformity, an angular luminanceuniformity, an angular luminous intensity uniformity or any combinationthereof within a region of the lightguide or of the surface or output ofthe light emitting region or light emitting device. In one embodiment, awidth of the light mixing region is selected from a range from 0.1 mm(for small displays) to more than 10 feet (for large billboards). In oneembodiment, the light mixing region is the region disposed along anoptical path near the end region of the coupling lightguides whereinlight from two or more coupling lightguides may inter-mix andsubsequently travel to a light emitting region of the lightguide. In oneembodiment, the light mixing region is formed from the same component ormaterial as at least one of the lightguide, lightguide region, lightinput coupler, and coupling lightguides.

Cladding Layer

In one embodiment, at least one of the light input coupler, couplinglightguide, light mixing region, lightguide region, and lightguideincludes a cladding layer optically coupled to at least one surface. Acladding region, as used herein, is a layer optically coupled to asurface wherein the cladding layer includes a material with a refractiveindex, n_(clad), less than the refractive index of the material, n_(m),of the surface to which it is optically coupled. In one embodiment,n_(m)-n_(clad) is one selected from the group of: 0.001-0.005,0.001-0.01, 0.001-0.1, 0.001-0.2, 0.001-0.3, 0.001-0.4, 0.01-0.1,0.1-0.5, 0.1-0.3, 0.2-0.5, greater than 0.01, greater than 0.1, greaterthan 0.2, and greater than 0.3. The cladding layer may be incorporatedto provide a separation layer between the core or core part of alightguide region and the outer surface to reduce undesirableout-coupling (for example, frustrated totally internally reflected lightby touching the film with an oily finger) from the core or core regionof a lightguide. In one embodiment, the cladding region is opticallycoupled to one or more surfaces of the light mixing region to preventout-coupling of light from the lightguide if the lightguide makescontact with another component. In this embodiment, the cladding alsoenables the cladding and light mixing region to be physically coupled toanother component. In one embodiment, the cladding is one selected fromthe group of methyl-based silicone pressure sensitive adhesive,fluoropolymer material (applied with using coating comprising afluoropolymer substantially dissolved in a solvent), and a fluoropolymerfilm. The cladding layer may be incorporated to provide a separationlayer between the core or core part of a lightguide region and the outersurface to reduce undesirable out-coupling (for example, frustratedtotally internally reflected light by touching the film with an oilyfinger) from the core or core region of a lightguide. Components orobjects such as additional films, layers, objects, fingers, dust etc.that come in contact or optical contact directly with a core or coreregion of a lightguide may couple light out of the lightguide, absorblight or transfer the totally internally reflected light into a newlayer. By adding a cladding layer with a lower refractive index than thecore, a portion of the light will totally internally reflect at thecore-cladding layer interface. Cladding layers may also be used toprovide the benefit of at least one of increased rigidity, increasedflexural modulus, increased impact resistance, anti-glare properties,provide an intermediate layer for combining with other layers such as inthe case of a cladding functioning as a tie layer or a base or substratefor an anti-reflection coating, a substrate for an optical componentsuch as a polarizer, liquid crystal material, increased scratchresistance, provide additional functionality (such as a low-tackadhesive to bond the lightguide region to another element, a window“cling type” film such as a highly plasticized PVC). The cladding layermay be an adhesive, such as a low refractive index silicone adhesivewhich is optically coupled to another element of the device, thelightguide, the lightguide region, the light mixing region, the lightinput coupler, or a combination of one or more of the aforementionedelements or regions. In one embodiment, a cladding layer is opticallycoupled to a rear polarizer in a backlit liquid crystal display. Inanother embodiment, the cladding layer is optically coupled to apolarizer or outer surface of a front-lit display such as anelectrophoretic display, e-book display, e-reader display, MEMs typedisplay, electronic paper displays such as E Ink® display by E InkCorporation, reflective or partially reflective LCD display, cholestericdisplay, or other display capable of being illuminated from the front.In another embodiment, the cladding layer is an adhesive that bonds thelightguide or lightguide region to a component such as a substrate(glass or polymer), optical element (such as a polarizer, retarder film,diffuser film, brightness enhancement film, protective film (such as aprotective polycarbonate film), the light input coupler, couplinglightguides, or other element of the light emitting device. In oneembodiment, the cladding layer is separated from the lightguide orlightguide region core layer by at least one additional layer oradhesive.

In one embodiment, a region of cladding material is removed or is absentin the region wherein the lightguide layer or lightguide is opticallycoupled to another region of the lightguide wherein the cladding isremoved or absent such that light can couple between the two regions. Inone embodiment, the cladding is removed or absent in a region near anedge of a lightguide, lightguide region, strip or region cut from alightguide region, or coupling lightguide such that light nearing theedge of the lightguide can be redirected by folding or bending theregion back onto a region of the lightguide wherein the cladding hasbeen removed where the regions are optically coupled together. Inanother embodiment, the cladding is removed or absent in the regiondisposed between the lightguide regions of two coupling lightguidesdisposed to receive light from a light source or near a light inputsurface. By removing or not applying or disposing a cladding in theregion between the input end of two or more coupling lightguidesdisposed to receive light from a light source, light is not directlycoupled into the cladding region edge.

In one embodiment, the cladding region is optically coupled to one ormore surfaces of the light mixing region to prevent out-coupling oflight from the lightguide if the lightguide makes contact with anothercomponent. In this embodiment, the cladding also enables the claddingand light mixing region to be physically coupled to another component.

Cladding Location

In one embodiment, the cladding region is optically coupled to one ormore of the following: a lightguide, a lightguide region, a light mixingregion, one surface of the lightguide, two surfaces of the lightguide, alight input coupler, coupling lightguides, and an outer surface of thefilm. In another embodiment, the cladding is disposed in optical contactwith the lightguide, the lightguide region, or a layer or layersoptically coupled to the lightguide and the cladding material is notdisposed on one or more coupling lightguides. In one embodiment, thecoupling lightguides do not include a cladding layer between the coreregions in the region near the light input surface or light source. Inthis embodiment, the core regions may be pressed or held together andthe edges may be cut and/or polished after stacking or assembly to forma light input surface or a light turning edge that is flat, curved, or acombination thereof. In another embodiment, the cladding layer is apressure sensitive adhesive and the release liner for the pressuresensitive adhesive is selectively removed in the region of one or morecoupling lightguides that are stacked or aligned together into an arraysuch that the cladding helps maintain the relative position of thecoupling lightguides relative to each other. In another embodiment, theprotective liner is removed from the inner cladding regions of thecoupling lightguides and is left on one or both outer surfaces of theouter coupling lightguides.

In one embodiment, a cladding layer is disposed on one or both oppositesurfaces of the light emitting region and is not disposed between two ormore coupling lightguides at the light input surface. For example, inone embodiment, a mask layer is applied to a film-based lightguidecorresponding to the end regions of the coupling lightguides that willform the light input surface after cutting and, in a particularembodiment the coupling lightguides, and the film is coated on one orboth sides with a low refractive index coating. In this embodiment, whenthe mask is removed and the coupling lightguides are folded (using, forexample a relative position maintaining element) and stacked, the lightinput surface comprises core layers without cladding layers and thelight emitting region comprise a cladding layer. The light mixing regionmay also comprise a cladding and/or light absorbing region in certainembodiments, which is beneficial for optical efficiency (light isdirected into the cladding at the input surface) and in applicationssuch as film-based frontlights for reflective or transflective displayswhere a cladding may be desired.

In another embodiment, the protective liner of at least one outersurface of the outer coupling lightguides is removed such that the stackof coupling lightguides may be bonded to one of the following: a circuitboard, a non-folded coupling lightguide, a light collimating opticalelement, a light turning optical element, a light coupling opticalelement, a flexible connector or substrate for a display or touchscreen,a second array of stacked coupling lightguides, a light input couplerhousing, a light emitting device housing, a thermal transfer element, aheat sink, a light source, an alignment guide, a registration guide orcomponent comprising a window for the light input surface, and anysuitable element disposed on and/or physically coupled to an element ofthe light input surface or light emitting device. In one embodiment, thecoupling lightguides do not comprise a cladding region on either planarside and optical loss at the bends or folds in the coupling lightguidesis reduced. In another embodiment, the coupling lightguides do notcomprise a cladding region on either planar side and the light inputsurface input coupling efficiency is increased due to the light inputsurface area having a higher concentration of lightguide receivedsurface relative to a lightguide with at least one cladding. In afurther embodiment, the light emitting region has at least one claddingregion or layer and the percentage of the area of the light inputsurface of the coupling lightguides disposed to transmit light into thelightguide portion of the coupling lightguides is greater than one ofthe following: 70%, 80%, 85%, 90%, 95%, 98% and 99%. The cladding may beon one side only of the lightguide or the light emitting device could bedesigned to be optically coupled to a material with a refractive indexlower than the lightguide, such as in the case with a plasticized PVCfilm (n=1.53) (or other low-tack material) temporarily adhered to aglass window (n=1.51).

In one embodiment, the cladding on at least one surface of thelightguide is applied (such as coated or co-extruded) and the claddingon the coupling lightguides is subsequently removed. In a furtherembodiment, the cladding applied on the surface of the lightguide (orthe lightguide is applied onto the surface of the cladding) such thatthe regions corresponding to the coupling lightguides do not have acladding. For example, the cladding material could be extruded or coatedonto a lightguide film in a central region wherein the outer sides ofthe film will comprise coupling lightguides. Similarly, the cladding maybe absent on the coupling lightguides in the region disposed in closeproximity to one or more light sources or the light input surface.

In one embodiment, two or more core regions of the coupling lightguidesdo not comprise a cladding region between the core regions in a regionof the coupling lightguide disposed within a distance selected from thegroup of 1 millimeter, 2 millimeters, 4 millimeters, and 8 millimetersfrom the light input surface edge of the coupling lightguides. In afurther embodiment, two or more core regions of the coupling lightguidesdo not comprise a cladding region between the core regions in a regionof the coupling lightguide disposed within a distance selected from thegroup of 10%, 20%, 50%, 100%, 200%, and 300% of the combined thicknessesof the cores of the coupling lightguides disposed to receive light fromthe light source from the light input surface edge of the couplinglightguides. In one embodiment, the coupling lightguides in the regionproximate the light input surface do not comprise cladding between thecore regions (but may contain cladding on the outer surfaces of thecollection of coupling lightguides) and the coupling lightguides areoptically coupled together with an index-matching adhesive or materialor the coupling lightguides are optically bonded, fused, orthermo-mechanically welded together by applying heat and pressure. In afurther embodiment, a light source is disposed at a distance to thelight input surface of the coupling lightguides less than one selectedfrom the group of 0.5 millimeter, 1 millimeter, 2 millimeters, 4millimeters, and 6 millimeters and the dimension of the light inputsurface in the first direction parallel to the thickness direction ofthe coupling lightguides is greater than one selected from the group of100%, 110%, 120%, 130%, 150%, 180%, and 200% the dimension of the lightemitting surface of the light source in the first direction. In anotherembodiment, disposing an index-matching material between the coreregions of the coupling lightguides or optically coupling or boding thecoupling lightguides together in the region proximate the light sourceoptically couples at least one selected from the group of 10%, 20%, 30%,40%, and 50% more light into the coupling lightguides than would becoupled into the coupling lightguides with the cladding regionsextending substantially to the light input edge of the couplinglightguide. In one embodiment, the index-matching adhesive or materialhas a refractive index difference from the core region less than oneselected from the group of 0.1, 0.08, 0.05, and 0.02. In anotherembodiment, the index-matching adhesive or material has a refractiveindex greater by less than one selected from the group of 0.1, 0.08,0.05, and 0.02 the refractive index of the core region. In a furtherembodiment, a cladding region is disposed between a first set of coreregions of coupling lightguides for a second set of coupling lightguidesan index-matching region is disposed between the core regions of thecoupling lightguides or they are fused together. In a furtherembodiment, the coupling lightguides disposed to receive light from thegeometric center of the light emitting area of the light source within afirst angle of the optical axis of the light source have claddingregions disposed between the core regions, and the core regions atangles larger than the first angle have index-matching regions disposedbetween the core regions of the coupling lightguides or they are fusedtogether. In one embodiment, the first angle is selected from the groupof 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, and 60degrees. In the aforementioned embodiments, the cladding region may be alow refractive index material or air. In a further embodiment, the totalthickness of the coupling lightguides in the region disposed to receivelight from a light source to be coupled into the coupling lightguides isless than n times the thickness of the lightguide region where n is thenumber of coupling lightguides. In a further embodiment, the totalthickness of the coupling lightguides in the region disposed to receivelight from a light source to be coupled into the coupling lightguides issubstantially equal to n times the thickness of the lightguide layerwithin the lightguide region.

Cladding Thickness

In a one embodiment, the average thickness of one or both claddinglayers of the lightguide is less than one selected from the group of:100 microns, 60 microns, 30 microns, 20 microns, 10 microns, 6 microns,4 microns, 2 microns, 1 micron, 0.8 microns, 0.5 microns, 0.3 microns,and 0.1 microns. In another embodiment, the ratio of the thickness ofthe core layer to one or more cladding layers is greater than oneselected from the group of 2, 4, 6, 8, 10, 20, 30, 40, and 60. In oneembodiment, a high core to cladding layer thickness ratio where thecladding extends over the light emitting region and the couplinglightguides enables more light to be coupled into the core layer at thelight input surface because the cladding regions represent a lowerpercentage of the surface area at the light input surface.

Cladding Layer Materials

In one embodiment, the cladding layer includes an adhesive such as asilicone-based adhesive, acrylate-based adhesive, epoxy, radiationcurable adhesive, UV curable adhesive, or other light transmittingadhesive. Fluoropolymer materials may be used as a low refractive indexcladding material and may be broadly categorized into one of two basicclasses. A first class includes amorphous fluoropolymers includinginterpolymerized units derived from vinylidene fluoride (VDF) andhexafluoropropylene (HFP) and optionally tetrafluoroethylene (TFE)monomers. The second significant class of fluoropolymers useful in oneembodiment are homo and copolymers based on fluorinated monomers such asTFE or VDF which do contain a crystalline melting point such aspolyvinylidene fluoride or thermoplastic copolymers of TFE such as thosebased on the crystalline microstructure of TFE-HFP-VDF. In anotherembodiment, the cladding includes a material with an effectiverefractive index less than the core layer due to microstructures ornanostructures. In another embodiment, the cladding layer includes aporous region including air or other gas or material with a refractiveindex less than 1.2 such that the effective refractive index of thecladding layer is reduced.

The cladding layer material may comprise light scattering domains andmay scatter light anisotropically or isotropically. In one embodiment,the cladding layer is an adhesive such as those described in U.S. Pat.No. 6,727,313 the contents of which are incorporated by referenceherein. In another embodiment, the cladding material comprises domainsless than 200 nm in size with a low refractive index such as thosedescribed in U.S. Pat. No. 6,773,801, the contents of which areincorporated by reference herein. Other low refractive index materials,fluoropolymer materials, polymers and adhesives may be used such asthose disclosed U.S. Pat. Nos. 6,887,334 and 6,827,886 and U.S. patentapplication Ser. No. 11/795,534, the contents of each are incorporatedby reference herein.

In another embodiment, a light emitting device comprises a lightguidewith a cladding on at least one side of a lightguide with a thicknesswithin one selected from the group of 0.1-10, 0.5-5, 0.8-2, 0.9-1.5,1-10, 0.1-1, and 1-5 times the 1/e penetration depth, λ_(e), at anangle, θ, selected from the group of 80, 70, 60, 50, 40, 30, 20, and 10degrees from the core-cladding interface normal within the lightguide. Alight output coupler or light extraction region (or film) is disposed tocouple a first portion of incident light out of the lightguide when inoptical contact with the cladding layer. For example, a removable andreplaceable light extraction film comprising high refractive index lightscattering features (such as TiO₂ or high refractive index glassparticles, beads, or flakes) is disposed upon the cladding layer of alightguide in a light fixture comprising a polycarbonate lightguide withan amorphous fluoropolymer cladding of thickness λ_(e). In the regionsof the removable and replaceable light extraction film with thescattering features, the light can be frustrated from the lightguide andescape the lightguide. In this embodiment, a light extraction film maybe used with a lightguide with a cladding region to couple light out ofthe lightguide. In this embodiment, a cladding region can help protectthe lightguide (from scratches, unintentional total internal reflectionfrustration or absorption when in contact with a surface, for example)while still allowing a removable and replaceable light extraction filmto allow for user configurable light output properties. In anotherembodiment, at least one film or component selected from the group of alight output coupling film, a distribution lightguide, and a lightextraction feature is optically coupled to, disposed upon, or formed ina cladding region and couples a first portion of light out of thelightguide and cladding region. In one embodiment the first portion isgreater than one selected from the group of 5%, 10%, 15%, 20%, 30%, 50%,and 70% of the flux within the lightguide or within the regioncomprising the thin cladding layer and film or component.

In one embodiment, the light input surface disposed to receive lightfrom the light source does not have a cladding layer. In one embodiment,the ratio of the cladding area to the core layer area at the light inputsurface is greater than 0 and less than one selected from the group of0.5, 0.4, 0.3, 0.2, 0.1, 0.05, 0.02, and 0.01. In another embodiment,the ratio of the cladding area to the core layer area in the regions ofthe light input surface receiving light from the light source with atleast 5% of the peak luminous intensity at the light input surface isgreater than 0 and less than one selected from the group of 0.5, 0.4,0.3, 0.2, 0.1, 0.05, 0.02, and 0.01.

Fluoropolymer materials may be used a low refractive index claddingmaterial and may be broadly categorized into one of two basic classes. Afirst class includes those amorphous fluoropolymers comprisinginterpolymerized units derived from vinylidene fluoride (VDF) andhexafluoropropylene (HFP) and optionally tetrafluoroethylene (TFE)monomers. Examples of such are commercially available from 3M Company asDyneon™ Fluoroelastomer FC 2145 and FT 2430. Additional amorphousfluoropolymers that can be used in embodiments are, for example,VDF-chlorotrifluoroethylene copolymers. One suchVDF-chlorotrifluoroethylene copolymer is commercially known as Kel-F™3700, available from 3M Company. As used herein, amorphousfluoropolymers are materials that contain essentially no crystallinityor possess no significant melting point as determined for example bydifferential scanning caloriometry (DSC). For the purpose of thisdiscussion, a copolymer is defined as a polymeric material resultingfrom the simultaneous polymerization of two or more dissimilar monomersand a homopolymer is a polymeric material resulting from thepolymerization of a single monomer.

The second significant class of fluoropolymers useful in an embodimentare those homo and copolymers based on fluorinated monomers such as TFEor VDF which do contain a crystalline melting point such aspolyvinylidene fluoride (PVDF, available commercially from 3M company asDyneon™ PVDF, or more preferable thermoplastic copolymers of TFE such asthose based on the crystalline microstructure of TFE-HFP-VDF. Examplesof such polymers are those available from 3M under the trade nameDyneon™ Fluoroplastics THV™ 200.

A general description and preparation of these classes of fluoropolymerscan be found in Encyclopedia Chemical Technology, FluorocarbonElastomers, Kirk-Othmer (1993), or in Modern Fluoropolymers, J. ScheirsEd, (1997), J Wiley Science, Chapters 2, 13, and 32. (ISBN0-471-97055-7), the contents of each are incorporated by referenceherein.

In one embodiment, the fluoropolymers are copolymers formed from theconstituent monomers known as tetrafluoroethylene (“TFE”),hexafluoropropylene (“HFP”), and vinylidene fluoride (“VdF,” “VF2,”).The monomer structures for these constituents are shown below as (1),(2) and (3): TFE: CF 2=CF 2 (1); VDF: CH 2=CF 2 (2); HFP: CF 2=CF-CF 3(3)

In one embodiment, the preferred fluoropolymer consists of at least twoof the constituent monomers (HFP and VDF), and more preferably all threeof the constituents monomers in varying molar amounts. Additionalmonomers not depicted above but may also be useful in an embodimentinclude perfluorovinyl ether monomers of the general structure: CF2=CF-OR f, wherein R f can be a branched or linear perfluoroalkylradical of 1-8 carbons and can itself contain additional heteroatomssuch as oxygen. Specific examples are perfluoromethyl vinyl ether,perfluoropropyl vinyl ether, and perfluoro(3-methoxy-propyl) vinylether. Additional examples incorporated by reference herein are found inWO00/12754 to Worm, assigned to 3M, and U.S. Pat. No. 5,214,100 toCarlson. Other fluoropolymer materials may be used such as thosedisclosed in U.S. patent application Ser. No. 11/026,614.

In one embodiment, the cladding material is birefringent and therefractive index in at least a first direction is less than refractiveindex of the lightguide region, lightguide core, or material to which itis optically coupled.

Collimated light traveling through a material may be reduced inintensity after passing through the material due to scattering(scattering loss coefficient), absorption (absorption coefficient), or acombination of scattering and absorption (attenuation coefficient). Inone embodiment, the cladding comprises a material with an averageabsorption coefficient for collimated light less than one selected fromthe group of 0.03 cm⁻¹, 0.02 cm⁻¹, 0.01 cm⁻¹, and 0.005 cm⁻¹ over thevisible wavelength spectrum from 400 nanometers to 700 nanometers. Inanother embodiment, the cladding comprises a material with an averagescattering loss coefficient for collimated light less than one selectedfrom the group of 0.03 cm⁻¹, 0.02 cm⁻¹, 0.01 cm⁻¹, and 0.005 cm⁻¹ overthe visible wavelength spectrum from 400 nanometers to 700 nanometers.In another embodiment, the cladding comprises a material with an averageattenuation coefficient for collimated light less than one selected fromthe group of 0.03 cm⁻¹, 0.02 cm⁻¹, 0.01 cm⁻¹, and 0.005 cm⁻¹ over thevisible wavelength spectrum from 400 nanometers to 700 nanometers.

In a further embodiment, a lightguide comprises a hard cladding layerthat substantially protects a soft core layer (such as a soft siliconeor silicone elastomer).

In one embodiment, a lightguide comprises a core material with aDurometer Shore A hardness (JIS) less than 50 and at least one claddinglayer with a Durometer Shore A hardness (JIS) greater than 50. In oneembodiment, a lightguide comprises a core material with an ASTM D638-10Young's Modulus less than 2 MPa and at least one cladding layer with anASTM D638-10 Young's Modulus greater than 2 MPa at 25 degrees Celsius.In another embodiment, a lightguide comprises a core material with anASTM D638-10 Young's Modulus less than 1.5 MPa and at least one claddinglayer with an ASTM D638-10 Young's Modulus greater than 2 MPa at 25degrees Celsius. In a further embodiment, a lightguide comprises a corematerial with an ASTM D638-10 Young's Modulus less than 1 MPa and atleast one cladding layer with an ASTM D638-10 Young's Modulus greaterthan 2 MPa at 25 degrees Celsius.

In one embodiment, a lightguide comprises a core material with an ASTMD638-10 Young's Modulus less than 2 MPa and the lightguide film has anASTM D638-10 Young's Modulus greater than 2 MPa at 25 degrees Celsius.In another embodiment, a lightguide comprises a core material with anASTM D638-10 Young's Modulus less than 1.5 MPa and the lightguide filmhas an ASTM D638-10 Young's Modulus greater than 2 MPa at 25 degreesCelsius. In one embodiment, a lightguide comprises a core material withan ASTM D638-10 Young's Modulus less than 1 MPa and the lightguide filmhas an ASTM D638-10 Young's Modulus greater than 2 MPa at 25 degreesCelsius.

In another embodiment, the cladding comprises a material with aneffective refractive index less than the core layer due tomicrostructures or nanostructures. In another embodiment, the claddinglayer comprises a porous region comprising air or other gas or materialwith a refractive index less than 1.2 such that the effective refractiveindex of the cladding layer is reduced. For example, in one embodiment,the cladding layer is an aerogel or arrangement of nano-structuredmaterials disposed on the core layer that have an effective refractiveindex less than the core layer. In one embodiment, the nano-structuredmaterial comprises fibers, particles, or domains with an averagediameter or dimension in the plane parallel to the core layer surface orperpendicular to the core layer surface less than one selected from thegroup of 1000, 500, 300, 200, 100, 50, 20, 10, 5, and 2 nanometers. Forexample, in one embodiment, the cladding layer is a coating comprisingnanostructured fibers, comprising polymeric materials including, withoutlimitation, at least one of the following: cellulose, polyester,polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polystyrene,polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), and otherlight transmitting or partially light transmitting materials. In anotherembodiment, materials that normally scatter too much light in bulk form(such as high-density polyethylene (HDPE) or polypropylene) to be usedas a core or cladding material for lightguide lengths greater than 1meter (such as scattering greater than 10% of the light out of thelightguide over the 1 meter length) are used in a nanostructured form.For example, in one embodiment, the nanostructured cladding material onthe film-based lightguide, when formed into a bulk solid form (such as a200 micron thick homogeneous film formed without mechanically formedphysical structures volumetrically or on the surface under filmprocessing conditions designed to minimize haze substantially) has anASTM haze greater than 0.5%.

In a further embodiment, the microstructured or nanostructured claddingmaterial comprises a structure that will “wet-out” or optically couplelight into a light extraction feature disposed in physical contact withthe microstructured or nanostructured cladding material. For example, inone embodiment, the light extraction feature comprises nanostructuredsurface features that when in close proximity or contact with thenanostructured cladding region couple light from the cladding region. Inone embodiment, the microstructured or nanostructured cladding materialhas complementary structures to the light extraction feature structures,such as a male-female part or other simple or complex complementarystructures such that the effective refractive index in the regioncomprising the two structures is larger than that of the cladding regionwithout the light extraction features.

Reflective Elements

In one embodiment, one or more of the: light source, the light inputsurface, the light input coupler, the coupling lightguide, lightguideregion, and the lightguide includes a reflective element or surfaceoptically coupled to it, disposed adjacent to it, or disposed to receivelight from it wherein the reflective region is one of a specularlyreflecting region, a diffusely reflecting region, a metallic coating ona region (such as an ITO coating, Aluminized PET, Silver coating, etc.),a multi-layer reflector dichroic reflector, a multi-layer polymericreflector, giant birefringent optical films, enhanced specular reflectorfilms, reflective ink or particles within a coating or layer, and awhite reflective film including one or more of the following: titaniumdioxide, Barium sulfate, and voids. In another embodiment, a lightemitting device comprises a lightguide wherein at least one lightreflecting material selected from the group of a light recyclingelement, a specularly reflective tape with a diffuse reflectance(specular component included) greater than 70%, a retroreflective film(such as a corner cube film or glass bead based retroreflective film),white reflecting film, and aluminum housing is disposed near oroptically coupled at least one edge region of the lightguide disposed toreceive light from the lightguide and redirect a first portion of lightback into the lightguide. In another embodiment, a light emitting devicecomprises a lightguide wherein at least one light absorbing materialselected from the group of a light absorbing tape with a diffusereflectance (specular component included) less than 50%, a regioncomprising a light absorbing dye or pigment, a region comprising carbonblack particles, a region comprising light absorbing ink, paint, filmsor surfaces, and a black material is disposed near or optically coupledat least one edge region of the lightguide disposed to receive lightfrom the lightguide and redirect a first portion of light back into thelightguide. In a further embodiment, a light reflecting material and alight absorbing material of the aforementioned types is disposed near oroptically coupled at least one edge region of the lightguide disposed toreceive light from the lightguide and redirect a first portion of lightback into the lightguide and absorb a second portion of incident light.In one embodiment, the light reflecting or light absorbing material isin the form of a line of ink or tape adhered onto the surface of thelightguide film. In one embodiment, the light reflecting material is aspecularly reflecting tape adhered to the top surface, edge, and bottomsurface of the lightguide near the edge of the lightguide. In anotherembodiment, the light absorbing material is a light absorbing tapeadhered to the top surface, edge, and bottom surface of the lightguidenear the edge of the lightguide. In another embodiment, the lightabsorbing material is a light absorbing ink or paint (such as a blackacrylic based paint) adhered to at least one selected from the group ofthe edge, the top surface near the edge, and the bottom surface near theedge of the lightguide film.

In one embodiment, the light emitting device is a backlight illuminatinga display or other object to be illuminated and the light emittingregion, lightguide, or lightguide region is disposed between areflective surface or element and the object to be illuminated. Inanother embodiment, the reflective element is a voided white PET filmsuch as TETORON® film UX Series from TEIJIN (Japan). In one embodiment,the reflective element or surface has a diffuse reflectance d/8 with thespecular component included (DR-SCI) measured with a Minolta CM508Dspectrometer greater than one selected from the group of 60%, 70%, 80%,90%, and 95%. In another embodiment, the reflective element or surfacehas a diffuse reflectance d/8 with the specular component excluded(DR-SCE) measured with a Minolta CM508D spectrometer greater than oneselected from the group of 60%, 70%, 80%, 90%, and 95%. In anotherembodiment, the reflective element or surface has a specular reflectancegreater than one selected from the group of 60%, 70%, 80%, 90%, and 95%.The specular reflectance, as defined herein, is the percentage of lightreflected from a surface illuminated by a 532 nanometer laser that iswithin a 10 degree (full angle) cone centered about the optical axis ofthe reflected light. This can be measured by using an integrating spherewherein the aperture opening for the integrating sphere is positioned ata distance from the point of reflection such that the angular extent ofthe captured light is 10 degrees full angle. The percent reflection ismeasured against a reflectance standard with a known specularreflectance, a reflectance standard, film, or object that have extremelylow levels of scattering.

In another embodiment, a light emitting device comprises a lightguidewherein at least one light reflecting material selected from the groupof a light recycling element, a specularly reflective tape with adiffuse reflectance (specular component included) greater than 70%, aretroreflective film (such as a corner cube film or glass bead basedretroreflective film), white reflecting film, and aluminum housing isdisposed near or optically coupled at least one edge region of thelightguide disposed to receive light from the lightguide and redirect afirst portion of light back into the lightguide. In another embodiment,a light emitting device comprises a lightguide wherein at least onelight absorbing material selected from the group of a light absorbingtape with a diffuse reflectance (specular component included) less than50%, a region comprising a light absorbing dye or pigment, a regioncomprising carbon black particles, a region comprising light absorbingink, paint, films or surfaces, and a black material is disposed near oroptically coupled at least one edge region of the lightguide disposed toreceive light from the lightguide and redirect a first portion of lightback into the lightguide. In a further embodiment, a light reflectingmaterial and a light absorbing material of the aforementioned types isdisposed near or optically coupled at least one edge region of thelightguide disposed to receive light from the lightguide and redirect afirst portion of light back into the lightguide and absorb a secondportion of incident light. In one embodiment, the light reflecting orlight absorbing material is in the form of a line of ink or tape adheredonto the surface of the lightguide film. In one embodiment, the lightreflecting material is a specularly reflecting tape adhered to the topsurface, edge, and bottom surface of the lightguide near the edge of thelightguide. In another embodiment, the light absorbing material is alight absorbing tape adhered to the top surface, edge, and bottomsurface of the lightguide near the edge of the lightguide. In anotherembodiment, the light absorbing material is a light absorbing ink orpaint (such as a black acrylic based paint) adhered to at least oneselected from the group of the edge, the top surface near the edge, andthe bottom surface near the edge of the lightguide film.

In one embodiment, the light emitting device is a backlight illuminatinga display or other object to be illuminated and the light emittingregion, lightguide, or lightguide region is disposed between areflective surface or element and the object to be illuminated. Inanother embodiment, the reflective element is a voided white PET filmsuch as TETORON® film UX Series from TEIJIN (Japan). In one embodiment,the reflective element or surface has a diffuse reflectance d/8 with thespecular component included (DR-SCI) measured with a Minolta CM508Dspectrometer greater than one selected from the group of 60%, 70%, 80%,90%, and 95%. In another embodiment, the reflective element or surfacehas a diffuse reflectance d/8 with the specular component excluded(DR-SCE) measured with a Minolta CM508D spectrometer greater than oneselected from the group of 60%, 70%, 80%, 90%, and 95%. In anotherembodiment, the reflective element or surface has a specular reflectancegreater than one selected from the group of 60%, 70%, 80%, 90%, and 95%.The specular reflectance, as defined herein, is the percentage of lightreflected from a surface illuminated by a 532 nanometer laser that iswithin a 10 degree (full angle) cone centered about the optical axis ofthe reflected light. This can be measured by using an integrating spherewherein the aperture opening for the integrating sphere is positioned ata distance from the point of reflection such that the angular extent ofthe captured light is 10 degrees full angle. The percent reflection ismeasured against a reflectance standard with a known specularreflectance, a reflectance standard, film, or object that have extremelylow levels of scattering.

Light Reflecting Optical Element is Also a Second Element

In addition to reflecting incident light, in one embodiment, the lightreflecting element is also at least one second element selected from thegroup of light blocking element, low contact area covering element,housing element, light collimating optical element, light turningoptical element and thermal transfer element. In another embodiment, thelight reflecting optical element is a second element within a region ofthe light reflecting optical element. In a further embodiment, the lightreflecting optical element comprises a bend region, tab region, holeregion, layer region, or extended region that is, or forms a componentthereof, a second element. For example, a diffuse light reflectingelement comprising a voided PET diffuse reflecting film may be disposedadjacent the lightguide region to provide diffuse reflection and thefilm may further comprise a specular reflecting metallized coating on anextended region of the film that is bent and functions to collimateincident light from the light source. In another embodiment, the secondelement or second region of the light reflecting optical element iscontiguous with one or more regions of the light reflecting opticalelement. In a further embodiment, the light reflecting optical elementis a region, coating, element or layer physically coupled to a secondelement. In another embodiment, the second element is a region, coating,element or layer physically coupled to a light reflecting opticalelement. For example, in one embodiment, the light reflecting opticalelement is a metalized PET film adhered to the back of a transparent,low contact area film comprising polyurethane and a surface reliefprofile wherein the film combination extends from beneath the lightguideregion to wrap around one or more coupling lightguides. In a furtherembodiment, the light reflecting optical element is physically and/oroptically coupled to the film-based lightguide and is cut during thesame cutting process that generates the coupling lightguides and thelight reflecting optical element is cut into regions that are angled,curved or subsequently angled or curved to form a light collimatingoptical element or a light turning optical element. In anotherembodiment, the light reflecting optical element may be opticallycoupled to the film-based lightguide by a pressure sensitive adhesiveand the light reflecting optical element may diffusely reflect,specularly reflect, or a combination thereof, a portion of the incidentlight. The size, shape, quantity, orientation, material and location ofthe tab regions, light reflecting regions or other regions of the lightreflecting optical element may vary as needed to provide optical(efficiency, light collimation, light redirection, etc.), mechanical(rigidity, connection with other elements, alignment, ease ofmanufacture etc.), or system (reduced volume, increased efficiency,additional functionality such as color mixing) benefits such as is knownin the art of optical elements, displays, light fixtures, etc. Forexample, the tab regions of a light reflecting optical element thatspecularly reflects incident light may comprise a parabolic, polynomialor other geometrical cross-sectional shape such that the angular FWHMintensity, light flux, orientation, uniformity, or light profile iscontrolled. For example, the curved cross-sectional shape of one or moretab regions may be that of a compound parabolic concentrator. In anotherembodiment, the light reflecting optical element comprises hole regions,tab regions, adhesive regions or other alignment, physical coupling,optical coupling, or positioning regions that correspond in shape, size,or location to other elements of the light emitting device to facilitateat least one selected from the group of alignment, position, adhesion,physically coupling, and optically coupling with a second element orcomponent of the light emitting device. For example, the lightreflecting optical element may be a specularly reflecting or mirror-likemetallized PET that is disposed beneath a substantially planar lightemitting region and extends into the region near the light source andcomprises extended tabs or folding regions that fold and are opticallycoupled to at least one outer surface of a light collimating element. Inthis embodiment, the light reflecting optical element is also acomponent of a light collimating optical element. In another embodiment,the light reflecting optical element is a specularly reflectingmetallized PET film that is optically coupled to a non-folded couplinglightguide using a pressure sensitive adhesive and is extended towardthe light source such that the extended region is optically coupled toan angled surface of a light collimating optical element that collimatesa portion of the light from the light source in the plane perpendicularto the plane comprising the surface of the non-folded couplinglightguide optically coupled to the light reflecting optical element.

In one embodiment, the light reflecting element is also a light blockingelement wherein the light reflecting element blocks a first portion oflight escaping the light input coupler, coupling lightguide, lightsource, light redirecting optical element, light collimating opticalelement, light mixing region, lightguide region. In another embodiment,the light reflecting element prevents the visibility of stray light,undesirable light, or a predetermined area of light emitting orredirecting surface from reaching the viewer of a display, sign, or alight emitting device. For example, a metallized specularly reflectingPET film may be disposed to reflect light from one side of thelightguide region back toward the lightguide region and also extend towrap around the stack of coupling lightguide using the PSA opticallycoupled to the coupling lightguides (which may be a cladding layer forthe lightguides) to adhere the metallized PET film to the stack andblock stray light escaping from the coupling lightguides and becomingvisible.

In one embodiment, the light reflecting element is also a low contactarea covering. For example, in one embodiment, the light reflectingelement is a metallized PET film comprising a methacrylate-based coatingthat comprises surface relief features. In this embodiment, the lightreflecting element may wrap around the stack without significantlyextracting light from the coupling lightguides when air is used as acladding region. In another embodiment, the reflective element hasnon-planar regions such that the reflective surface is not flat and thecontact area between the light reflecting film and one or more couplinglightguides or lightguide regions is a low percentage of the exposedsurface area.

In another embodiment, the light reflecting element is also a housingelement, for example, in one embodiment the light reflecting element isa reflective coating on the inner wall of the housing for the couplinglightguides. The housing may have reflective surfaces or reflect lightfrom within (such as an internal reflecting layer or material). Thelight reflecting element may be the housing for the lightguide region orother lightguide or component of the light emitting device.

In a further embodiment, the light reflecting element is also a lightcollimating optical element disposed to reduce the angular full-width athalf maximum intensity of light from a light source before the lightenters one or more coupling lightguides. In one embodiment, the lightreflecting optical element is a specularly reflecting multilayer polymerfilm (such as a giant birefringent optical film) disposed on one side ofthe light emitting region of lightguide film and extended in a directiontoward the light source with folds or curved regions that are bent orfolded to form angled or curved shapes that receive light from the lightsource and reflect and collimate light toward the input surface of oneor more coupling lightguides. More than one fold or curved region may beused to provide different shapes or orientations of light reflectingsurfaces for different regions disposed to receive light from the lightsource. For example, an specularly reflecting multilayer polymer film(such as a giant birefringent optical film) disposed and opticallycoupled to the lightguide region of a film-based lightguide using a lowrefractive index PSA cladding layer may extend toward the light sourceand comprise a first extended region that wraps around the claddingregion to protect and block stray light and further comprise an extendedregion that comprises two tabs that are folded and a cavity wherein thelight source may be disposed such that light from the light sourcewithin a first plane is collimated by the extended region tabs. In oneembodiment, the use of the light reflecting element that is physicallycoupled to another component in the light emitting device (such as thefilm-based lightguide or coupling lightguides) provides an anchor orregistration assistance for aligning the light collimating opticalelement tabs or reflective regions of the light reflecting element.

In a further embodiment, the light reflecting element is also a lightturning optical element disposed to redirect the optical axis of lightin a first plane. In one embodiment, the light reflecting opticalelement is a specularly reflecting multilayer polymer film (such as agiant birefringent optical film) disposed on one side of the lightemitting region of lightguide film and extended in a direction towardthe light source with folds or curved regions that are bent or folded toform angled or curved shapes that receive light from the light sourceand reflect and redirect the optical axis of the incident light towardthe input surface of one or more coupling lightguides. More than onefold or curved region may be used to provide different shapes ororientations of light reflecting surfaces for different regions disposedto receive light from the light source. For example, a specularlyreflecting multilayer polymer film (such as a giant birefringent opticalfilm) film disposed and optically coupled to the lightguide region of afilm-based lightguide using a low refractive index PSA cladding layermay extend toward the light source and comprise an first extended regionthat wraps around the cladding region to protect and block stray lightand further comprise an extended region that comprises two tabs that arefolded and a cavity wherein the light source may be disposed such thatoptical axis of the light from the light source within a first plane ina first direction is redirected by the extended region tabs into asecond direction different than the first direction. In one embodiment,the use of the light reflecting element that is physically coupled toanother component in the light emitting device (such as the film-basedlightguide or coupling lightguides) provides an anchor or registrationassistance for aligning the light turning optical element tabs orreflective regions of the light reflecting element.

Housing or Holding Device for Light Input Coupler

In one embodiment, a light emitting device includes a housing or holdingdevice that holds or contains at least part of a light input coupler anda light source. The housing or holding device may house or containwithin one or more of the following: a light input coupler, a lightsource, coupling lightguides, a lightguide, optical components,electrical components, a heat sink or other thermal components,attachment mechanisms, registration mechanisms, folding mechanismsdevices, and frames. The housing or holding device may include aplurality of components or any combination of the aforementionedcomponents. The housing or holding device may serve one or more of thefollowing functions, as well as other suitable functions: protectingfrom dust and debris contamination, providing an air-tight seal,providing a water-tight seal, housing or containing components,providing a safety housing for electrical or optical components,assisting with folding or bending the coupling lightguides, assisting inaligning or holding the lightguide, coupling lightguide, light source orlight input coupler relative to another component, maintaining thearrangement of the coupling lightguides, recycling light (such as withreflecting inner walls), providing attachment mechanisms for attachingthe light emitting device to an external object or surface, providing anopaque container such that stray light does not escape through specificregions, providing a translucent surface for displaying indicia orproviding illumination to an object external to the light emittingdevice, including a connector for release and interchangeability ofcomponents, and providing a latch or connector to connect with otherholding devices or housings.

In one embodiment, the housing or holding device includes one or more ofthe following: a connector, a pin, a clip, a latch, an adhesive region,a clamp, a joining mechanism, and one or more other suitable connectingelements or mechanical means to connect or hold the housing or holdingdevice to another housing or holding device, a lightguide, a couplinglightguide, a film, a cartridge, a removable component or components, astrip, an exterior surface such as a window or automobile, a lightsource, electronics or electrical components, a circuit board for theelectronics or a light source such as an LED, a heat sink or one or moreother suitable thermal control elements, a frame of the light emittingdevice, and other suitable components of the light emitting device.

In another embodiment, one or more input ends and/or one or more outputends of the coupling lightguides are held in physical contact with arelative position maintaining element by one or more of the following:magnetic grips, mechanical grips, clamps, screws, mechanical adhesion,chemical adhesion, dispersive adhesion, diffusive adhesion,electrostatic adhesion, vacuum holding, and an adhesive.

Curved or Flexible Housing

In another embodiment, the housing includes at least one curved surface.A curved surface can permit non-linear shapes or devices or facilitateincorporating non-planer or bent lightguides or coupling lightguides. Inone embodiment, a light emitting device includes a housing with at leastone curved surface wherein the housing includes curved or bent couplinglightguides. In another embodiment, the housing is flexible such thatthe housing may be bent temporarily, permanently or semi-permanently. Byusing a flexible housing, for example, the light emitting device may beable to be bent such that the light emitting surface is curved alongwith the housing, or the light emitting area may curve around a bend ina wall or corner, for example. In one embodiment, the housing orlightguide may be bent temporarily such that the initial shape issubstantially restored (bending a long housing to get it through a doorfor example).

Housing Including a Thermal Transfer Element

In one embodiment, the housing includes a thermal transfer elementdisposed to transfer heat from a component within the housing to anouter surface of the housing. In another embodiment, the thermaltransfer element includes one or more of the following: a heat sink, ametallic or ceramic element, a fan, a heat pipe, a synthetic jet, anair-jet producing actuator, an active cooling element, a passive coolingelement, a rear portion of a metal core or other conductive circuitboard, a thermally conductive adhesive, or one or more other suitablecomponents known to thermally conduct heat. In one embodiment, thethermal transfer element has a thermal conductivity (W/(m·K)) greaterthan one selected from the group of: 0.2, 0.5, 0.7, 1, 3, 5, 50, 100,120, 180, 237, 300, and 400.

Low Contact Area Cover

In one embodiment, a low contact area cover is disposed between at leastone coupling lightguide and the exterior to the light emitting device.The low contact area provides a low surface area of contact with aregion of the lightguide or a coupling lightguide and may furtherprovides one or more of the following: protection from fingerprints,protection from dust or air contaminants, protection from moisture,protection from internal or external objects that would decouple orabsorb more light than the low contact area cover when in contact in oneor more regions with one or more coupling lightguides, a means forholding or containing at least one coupling lightguide, holding therelative position of one or more coupling lightguides, and preventingthe coupling lightguides from unfolding into a larger volume or contactwith a surface that could de-couple or absorb light. In one embodiment,the low contact area cover is disposed substantially around one or morecoupling lightguide stacks or arrays and facilitates one or more of thefollowing: reducing the dust buildup on the coupling lightguides,protecting one or more coupling lightguides from frustrated totalinternal reflection or absorption by contact with another lighttransmitting or absorbing material, and preventing or limitingscratches, cuts, dents, or deformities from physical contact with othercomponents, assemblers, or users of the device.

In one embodiment, the low contact area cover is a film with at leastone of a lower refractive index than the refractive index of the outermaterial of the coupling lightguide disposed near the low contact areacover, and surface relief pattern or structure on the surface of thefilm-based low contact area cover disposed near at least one couplinglightguide. In one embodiment, the low contact area cover is a sheet,film, or component including one or more of the following: paper,fibrous film or sheet, cellulosic material, pulp, low-acidity paper,synthetic paper, flashspun fibers, flashspun high-density polyethylenefibers, and a micro-porous film. In another embodiment, the filmmaterial of the low contact area cover or the area of the low contactarea cover in contact with the core layer of the lightguide in the lightemitting region includes a material with a refractive index in adirection parallel or perpendicular to the core surface less than oneselected from the group of: 1.6, 1.55, 1.5, 1.45, 1.41, 1.38, 1.35,1.34, 1.33, 1.30, 1.25, and 1.20. In another embodiment, the filmsurface features that substantially prevent optical coupling includemicrostructured and/or nanostructured features that couple less than oneselected from the group of: 40%, 30%, 20%, 10%, 5%, 2% and 1% of theincident light in the lightguide out of the lightguide. In oneembodiment, the light extraction region features, the features thatsubstantially prevent optical coupling, or the low contact area coverfeatures include a fibrous material with a specific surface(surface/mass ratio) greater than one selected from the group of: 0.1,0.5, 1, 5, 10, 20, 30, 40, and 50 m²/g.

Lightguide Thickness and Properties

In one embodiment, the thickness of the film, lightguide and/orlightguide region is within a range of 0.005 mm to 0.5 mm. In anotherembodiment, the thickness of the film or lightguide is within a range of0.025 mm (0.001 inches) to 0.5 mm (0.02 inches). In a furtherembodiment, the thickness of the film, lightguide and/or lightguideregion is within a range of 0.050 mm to 0.175 mm. In one embodiment, thethickness of the film, lightguide or lightguide region is less than 0.2mm or less than 0.5 mm. In one embodiment, one or more of a thickness, alargest thickness, an average thickness, greater than 90% of the entirethickness of the film, a lightguide, and a lightguide region is lessthan 0.2 millimeters. In one embodiment, at least one selected from thegroup of thickness, largest thickness, average thickness, greater than90% of the entire thickness of the film, lightguide, and lightguideregion is less than 0.2 millimeters. In another embodiment, the size tothickness ratio, defined as the largest dimension of the light emittingregion in the plane of the light emitting region divided by the averagethickness of the core region within the light emitting region is greaterthan one selected from the group of 100; 500; 1,000; 3,000; 5,000;10,000; 15,000; 20,000; 30,000; and 50,000.

In one embodiment, a light emitting device comprises a light source, alight input coupler, and a film-based lightguide wherein the averagelight flux density in the coupling lightguides, light mixing region,lightguide region, or light emitting region within the film-basedlightguide is greater than one selected from the group of 5, 10, 20, 50,100, 200, 300, 500, and 1000 lumens per square millimeter. In anotherembodiment, a light emitting device comprises a light source, a lightinput coupler, and a film-based lightguide wherein the maximum lightflux density in the coupling lightguides, light mixing region,lightguide region, or light emitting region within the film-basedlightguide is greater than one selected from the group of 5, 10, 20, 50,100, 200, 300, 500, and 1000 lumens per square millimeter. The fluxdensity in a region is measured by cutting an optical quality edgeperpendicular to the surface at the region and masking off the areaaround the region (using light absorbing materials such that light isnot substantially reflected back into the film) and measuring the farfield luminous intensity using a goniophotometer.

Optical Properties of the Lightguide or Light Transmitting Material

With regards to the optical properties of lightguides or lighttransmitting materials for certain embodiments, the optical propertiesspecified herein may be general properties of the lightguide, the core,the cladding, or a combination thereof or they may correspond to aspecific region (such as a light emitting region, light mixing region,or light extracting region), surface (light input surface, diffusesurface, flat surface), and direction (such as measured normal to thesurface or measured in the direction of light travel through thelightguide). In one embodiment, an average luminous transmittance of thelightguide measured within at least one of the light emitting region,the light mixing region, and the lightguide according to ASTM D1003 witha BYK Gardner haze meter is greater than one selected from the group of:70%, 80%, 88%, 92%, 94%, 96%, 98%, and 99%; the average haze is lessthan one selected from the group of: 70%, 60%, 50%, 40%, 30%, 20%, 10%,5% and 3%; and the average clarity is greater than one selected from thegroup of: 70%, 80%, 88%, 92%, 94%, 96%, 98%, and 99%.

Refractive Index of the Light Transmitting Material

In one embodiment, the core material of the lightguide has a highrefractive index and the cladding material has a low refractive index.In one embodiment, the core is formed from a material with a refractiveindex (n_(D)) greater than one selected from the group of: 1.3, 1.4,1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8,2.9, and 3.0. In another embodiment, the refractive index (n_(D)) of thecladding material is less than one selected from the group of: 1.1, 1.2,1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, and 2.5.

In one embodiment, the core or the cladding or other light transmittingmaterial may be a thermoplastic, thermoset, rubber, polymer, silicone orother light transmitting material. Optical products can be prepared fromhigh index of refraction materials, including monomers such as highindex of refraction (meth)acrylate monomers, halogenated monomers, andother suitable high index of refraction monomers as are known in theart.

Shape of the Lightguide

In one embodiment, at least a portion of the lightguide shape orlightguide surface is substantially planar, curved, cylindrical, aformed shape from a substantially planar film, spherical, partiallyspherical, angled, twisted, rounded, have a quadric surface, spheroid,cuboid, parallelepiped, triangular prism, rectangular prism, ellipsoid,ovoid, cone pyramid, tapered triangular prism, wave-like shape, and/orother known suitable geometrical solids or shapes. In one embodiment,the lightguide is a film formed into a shape by thermoforming or othersuitable forming techniques. In another embodiment, the film or regionof the film is tapered in at least one direction. In a furtherembodiment, a light emitting device includes a plurality of lightguidesand a plurality of light sources physically coupled or arranged together(such as tiled in a 1×2 array for example). In another embodiment, thelightguide region of the film is substantially in the shape of arectangle, a square, a circle, a toroid or doughnut (elliptical with ahole in the inner region), an ellipse, a linear strip, or a tube (with acircular, rectangular, polygonal, or other suitable shapedcross-section). In one embodiment, a light emitting device includes alightguide formed from a film into a hollow cylindrical tube includingcoupling lightguide strips branching from the film on a short edgetoward an inner portion of the cylinder. In another embodiment, a lightemitting device includes a film lightguide with coupling lightguides cutinto the film so that the coupling lightguides remain coupled to thelightguide region and the central strip is not optically coupled to thelightguide and provides a spine with increased stiffness in at least onedirection near the central strip region or lightguide region near thestrip.

Tiled Lightguides

In a further embodiment, a light emitting device includes lightguideswith light input couplers arranged such that the light source isdisposed in the central region of the edge of the lightguide, and thelight input coupler (or a component thereof) does not extend past theedge to enable the lightguides to be tiled in a suitable array, such asa 1×2, 2×2, 2×3, 3×3, or larger array. In another embodiment, a lightemitting device includes light emitting lightguides with a lowseparation distance wherein the separation between the lightguides in atleast one direction along the light emitting surface is less than oneselected from the group of: 10 mm, 5 mm, 3 mm, 2 mm, 1 mm and 0.5 mm.

In one embodiment, the light emitting device includes a linear array oflightguides in a first direction. In another embodiment, a lightemitting device includes a linear array of lightguides in a firstdirection and a linear array of lightguides in a second directionorthogonal to the first direction. In a further embodiment, a lightemitting device includes a rectangular matrix of lightguides. In lightemitting devices including tiled lightguides, the light input couplers,the coupling lightguides, and/or the one or more light sources may bedisposed along the periphery of the tiled lightguides, between thelateral edges of the lightguides along the side of the lightguide,folded back toward the central region between the lateral edges, orfolded underneath or above the lightguide to permit a low separationdistance between the lightguides and/or light emitting regions.

In another embodiment, the lightguide includes a single fold or bendnear an edge of the lightguide such that the lightguide folds under orover onto and optically coupled to itself. In this embodiment, lightwhich would ordinarily be lost at the edge of a lightguide may befurther extracted from the lightguide after the fold or bend to increasethe optical efficiency of the lightguide or device. In anotherembodiment, the light extraction features on the lightguide disposed inthe optical path of the light within the lightguide after the fold orbend near an edge provide light extraction features that increase one ormore of the following: a luminance, a luminance uniformity, a coloruniformity, an optical efficiency, an image or logo clarity andresolution.

Lightguide Material

In one embodiment, a light emitting device includes a lightguide orlightguide region formed from at least one light transmitting material.In one embodiment, the lightguide is a film includes at least one coreregion and at least one cladding region, each including at least onelight transmitting material. In one embodiment, the light transmittingmaterial is a thermoplastic, thermoset, rubber, polymer, hightransmission silicone, glass, composite, alloy, blend, silicone, orother suitable light transmitting material, or a combination thereof. Inone embodiment, a component or region of the light emitting deviceincludes a suitable light transmitting material, such as one or more ofthe following: cellulose derivatives (e.g., cellulose ethers such asethylcellulose and cyanoethylcellulose, cellulose esters such ascellulose acetate), acrylic resins, styrenic resins (e.g., polystyrene),polyvinyl-series resins [e.g., poly(vinyl ester) such as poly(vinylacetate), poly(vinyl halide) such as poly(vinyl chloride), polyvinylalkyl ethers or polyether-series resins such as poly(vinyl methylether), poly(vinyl isobutyl ether) and poly(vinyl t-butyl ether)],polycarbonate-series resins (e.g., aromatic polycarbonates such asbisphenol A-type polycarbonate), polyester-series resins (e.g.,homopolyesters, for example, polyalkylene terephthalates such aspolyethylene terephthalate and polybutylene terephthalate, polyalkylenenaphthalates corresponding to the polyalkylene terephthalates;copolyesters containing an alkylene terephthalate and/or alkylenenaphthalate as a main component; homopolymers of lactones such aspolycaprolactone), polyamide-series resin (e.g., nylon 6, nylon 66,nylon 610), urethane-series resins (e.g., thermoplastic polyurethaneresins), copolymers of monomers forming the above resins [e.g., styreniccopolymers such as methyl methacrylate-styrene copolymer (MS resin),acrylonitrile-styrene copolymer (AS resin), styrene-(meth)acrylic acidcopolymer, styrene-maleic anhydride copolymer and styrene-butadienecopolymer, vinyl acetate-vinyl chloride copolymer, vinyl alkylether-maleic anhydride copolymer]. Incidentally, the copolymer may bewhichever of a random copolymer, a block copolymer, or a graftcopolymer. In one embodiment, a thermoset material is coated onto athermoplastic film wherein the thermoset material is the core materialand the cladding material is the thermoplastic film or material. Inanother embodiment, a first thermoset material is coated onto a filmincluding a second thermoset material wherein the first thermosetmaterial is the core material, and the cladding material is the secondthermoset plastic.

Lightguide Material Comprises Glass

In one embodiment, the coupling lightguides include a core materialincluding a glass material. In one embodiment, the glass material is oneselected from the group of: fused silica, synthetic amorphous silicondioxide, optical grade fused quartz, synthetic fused silica,borosilicate glass, crown glass, and aluminoborosilicate glass. Inanother embodiment, the core material includes a glass which is coated,or has an organic material applied to one or more of the following: anedge, a top surface, and a bottom surface. In one embodiment, thecoating on the glass functions to provide a cladding region, increaseimpact resistance, and/or provide increased flexibility. In anotherembodiment, the coupling lightguides comprising glass, a polymericmaterial, or a rubber material are heated to a temperature above theirglass transition temperature or VICAT softening point before folding ina first direction.

Outermost Surface of the Film or Lightguide

In one embodiment, the outermost surface of the film, lightguide orlightguide region includes one or more of the following: cladding,surface texture to simulate a soft feel or match the surface texture ofcloth or upholstery, a refractive element to redirect or collimate lightfrom the light extraction features (such as microlens array), anadhesive layer, a removable backing material, an anti-reflection coatingor surface, an anti-glare coating or surface, and a rubber surface. Inone embodiment, the outermost surface of the film, lightguide, lightemitting film, light redirecting element, or light emitting deviceincludes surface relief features and the ASTM D523-89 60 degree gloss ofthe surface is less than one selected from the group of: 100, 50, 25,and 15 gloss units. In one embodiment, the gloss on the outer surfacereduces ambient glare light intensity that would highlight the surface.For example, in one embodiment, the light emitting device includes alightguide with an outermost surface with a uniform low gloss of 2 glossunits. When this lightguide is disposed on a wall with a matte ordiffusing surface with a gloss of about 2 gloss units, the substantiallytransparent lightguide with high visible light transmittance is nearlyinvisible, even at glare angles from light sources due to the matchingof the gloss of the outermost surface. In this embodiment, the lightemitting device is significantly less visible in the off-state in anapplication such as a wall mounted light fixture. In one embodiment, theoutermost surface with the low gloss is a surface of an anti-glare film,embossed film, cladding layer, light redirecting element, light turningoptical element, light collimating optical element, lightguide, coreregion (where there is no cladding surface on that side of the coreregion), light re-directing element, light emitting device cover, lens,or a housing element.

In one embodiment, the outermost surface of the film, lightguide, lightemitting film, light redirecting element, or light emitting device hasan ASTM D523-89 60 degree gloss greater than one selected from the groupof: 50, 70, 90, 100, and 110 gloss units. In this embodiment, the highgloss can match a glossy surface such as a window, glass partition, ormetal surface, for example, such that the component is less visible inthe off state at glare angles. In another embodiment, a kit includes alight emitting device and one or more films with gloss levels differentfrom a region of the outermost surface of the light emitting device thatmay be attached to an outermost surface region of the light emittingdevice to allow a choice of gloss level for the new outermost surface.For example, a film with the correct gloss level may be chosen to matchthe gloss level of the wall adjacent the light emitting device.

Light Extraction Method

In one embodiment, one or more of the lightguide, the lightguide region,and the light emitting region includes at least one light extractionfeature or region. In one embodiment, the light extraction region may bea raised or recessed surface pattern or a volumetric region. Raised andrecessed surface patterns include, without limitation, scatteringmaterial, raised lenses, scattering surfaces, pits, grooves, surfacemodulations, microlenses, lenses, diffractive surface features,holographic surface features, photonic bandgap features, wavelengthconversion materials, holes, edges of layers (such as regions where thecladding is removed from covering the core layer), pyramid shapes, prismshapes, and other geometrical shapes with flat surfaces, curvedsurfaces, random surfaces, quasi-random surfaces, and combinationsthereof. The volumetric scattering regions within the light extractionregion may include dispersed phase domains, voids, absence of othermaterials or regions (gaps, holes), air gaps, boundaries between layersand regions, and other refractive index discontinuities within thevolume of the material different that co-planar layers with parallelinterfacial surfaces.

In one embodiment, the light extraction feature is substantiallydirectional and includes one or more of the following: an angled surfacefeature, a curved surface feature, a rough surface feature, a randomsurface feature, an asymmetric surface feature, a scribed surfacefeature, a cut surface feature, a non-planar surface feature, a stampedsurface feature, a molded surface feature, a compression molded surfacefeature, a thermoformed surface feature, a milled surface feature, anextruded mixture, a blended materials, an alloy of materials, acomposite of symmetric or asymmetrically shaped materials, a laserablated surface feature, an embossed surface feature, a coated surfacefeature, an injection molded surface feature, an extruded surfacefeature, and one of the aforementioned features disposed in the volumeof the lightguide. For example, in one embodiment, the directional lightextraction feature is a 100 micron long, 45 degree angled facet grooveformed by UV cured embossing a coating on the lightguide film thatsubstantially directs a portion of the incident light within thelightguide toward 0 degrees from the surface normal of the lightguide.

In one embodiment, the light extraction feature is a specularly,diffusive, or a combination thereof reflective material. For example,the light extraction feature may be a substantially specularlyreflecting ink disposed at an angle (such as coated onto a groove) orthe light extraction feature may be a substantially diffusely reflectiveink such as an ink including titanium dioxide particles within amethacrylate-based binder.

In one embodiment, the light extraction feature is a protruding featureon a film or component that is applied to the core or cladding region ofa lightguide. In one embodiment, the light extraction features areprotrusions from a film that are pressed into a thin cladding such thatthe separation between the core and the cladding is reduced such thatthe evanescent penetration depth of light in the cladding permitsfrustration of a first portion of the light into the material of thelight extraction feature (or scattering therefrom in the case of ascattering light extraction feature such as a TiO₂ particle). In oneembodiment, a lightguide includes a high refractive index core layer anda compressible, thin low refractive index material such that when aforce greater than one selected from the group of: 1, 2, 5, 10, 20, 40,and 50 pounds per square inch, a first portion of light is frustratedfrom the lightguide. For example, in one embodiment, a light extractionfilm including a pattern of light scattering ink including TiO₂particles is physically coupled to a compressible fluoropolymer claddingwith a first thickness on a film-based lightguide including apolycarbonate core layer. A glass plate compresses the light extractionfilm onto the cladding layer such that the thickness of the claddinglayer reduces to a second thickness and a first portion of the lightfrom the lightguide is scattered from the lightguide due to theevanescent coupling of the light through the cladding to the lightscattering ink.

In one embodiment, a light extraction feature film includes protrudinglight extraction features that adhere to the core region and function asstandoffs and adhesion locations to hold the light extraction featurefilm in place and to protect the light emitting region. In thisembodiment, an air cladding is disposed between the light extractionfeatures along the surface of the core layer. For example, in oneembodiment, a light emitting device includes a light extraction featurefilm having 100 micron protrusions made of light scattering ink and apressure sensitive adhesive disposed in a pattern on the surface of apolyethylene terephthalate (PET) film. The light extraction feature filmis laminated to the core layer and bonded in the light extractionfeature adhesive protrusions. In this embodiment, the light extractionfeature film protects the core layer from scratches or dust/dirtaccumulation that can occur during assembly, shipping or end-use.

In one embodiment, the light extraction features comprise an ink ormaterial within a binder comprising least one selected from the group oftitanium dioxide, barium sulfate, metal oxides, microspheres or othernon-spherical particles comprising polymers (such as PMMA, polystyrene),rubber, or other inorganic materials. In one embodiment, the ink ormaterial is deposited by one selected from the group of thermal inkjetprinting, piezoelectric inkjet printing, continuous inkjet printing,screen printing (solvent or UV), laser printing, sublimation printing,dye-sublimation printing, UV printing, toner-based printing, LED tonerprinting, solid ink printing, thermal transfer printing, impactprinting, offset printing, rotogravure printing, photogravure printing,offset printing, flexographic printing, hot wax dye transfer printing,pad printing, relief printing, letterpress printing, xerography, solidink printing, foil imaging, foil stamping, hot metal typesetting,in-mold decoration, and in-mold labeling.

Visibility of Light Extraction Features

In one embodiment, at least one light extraction region includes lightextraction features which have a low visibility to the viewer when theregion is not illuminated by light from within the lightguide (such aswhen the device is in the off-state or the particular lightguide in amulti-lightguide device is not illuminated). In one embodiment, theluminance at a first measurement angle of one or more of a lightguideregion, a square centimeter measurement area of the light emittingsurface corresponding to light redirected by at least one lightextraction feature, a light emitting region, a light extraction feature,and a light extracting surface feature or collection of light extractionfeatures is less than one selected from the group of: 0.5 cd/m², 1cd/m², 5 cd/m², 10 cd/m², 50 cd/m², and 100 cd/m² when exposed todiffuse illuminance from an integrating sphere of one selected from thegroup of: 10 lux, 50 lux, 75 lux, 100 lux, 200 lux, 300 lux, 400 lux,500 lux, 750 lux, and 1000 lux when place over a black, light absorbingsurface. Examples of a suitable light absorbing surface include, withoutlimitation, a black velour cloth material, a black anodized aluminum, amaterial with a diffuse reflectance (specular component included) lessthan 5%, and a window to a light trap box (a box with light absorbingblack velour or other material lining the walls). In one embodiment, thefirst measurement angle for the luminance is one selected from the groupof 0 degrees, 5 degrees, 8 degrees, 10 degrees, 20 degrees, 40 degrees,0-10 degrees, 0-20 degrees, 0-30 degrees, and 0-40 degrees. In oneembodiment, the luminance of the light emitted from a 1 cm² measurementarea of the light emitting surface corresponding to light redirected byat least one light extracting feature is less than 100 cd/m2 whenexposed to a diffuse illuminance of 200 lux from an integrating spherewhen placed over Light Absorbing Black-Out Material from Edmund Optics.In another embodiment, the luminance of the light emitted from a 1 cm²measurement area of the light emitting surface corresponding to lightredirected by at least one light extracting feature is less than 50cd/m² when exposed to a diffuse illuminance of 200 lux from anintegrating sphere when placed over Light Absorbing Black-Out Materialfrom Edmund Optics Inc. In another embodiment, the luminance of thelight emitted from a 1 cm² measurement area of the light emittingsurface corresponding to light redirected by at least one or an averageof all light extracting features is less than 25 cd/m² when exposed to adiffuse illuminance of 200 lux from an integrating sphere when placedover Light Absorbing Black-Out Material from Edmund Optics. In oneembodiment, the thin lightguide film permits smaller features to be usedfor light extraction features or light extracting surface features to bespaced further apart due to the thinness of the lightguide. In oneembodiment, the average largest dimensional size of the light extractingsurface features in the plane parallel to the light emitting surfacecorresponding to a light emitting region of the light emitting device isless than one selected from the group of: 3 mm, 2 mm, 1 mm, 0.5 mm, 0.25mm, 0.1 mm, 0.080 mm, 0.050 mm, 0.040 mm, 0.025 mm, and 0.010 mm.

In one embodiment, the individual light extracting surface features,regions, or pixels are not discernable as an individual pixel when thedevice is emitting light in an on state and is not readily discernablewhen the light emitting device is in the off state when viewed at adistance greater than one selected from the group of 10 centimeters, 20centimeters, 30 centimeters, 40 centimeters, 50 centimeters, 100centimeters, and 200 centimeters. In this embodiment, the area mayappear to be emitting light, but the individual pixels or sub-pixelscannot be readily discerned from one another. In another embodiment, theintensity or color of a light emitting region of the light emittingdevice is controlled by spatial or temporal dithering or halftoneprinting. In one embodiment, the average size of the light extractingregions in a square centimeter of a light emitting region on the outersurface of the light emitting device is less than 500 microns and thecolor and/or luminance is varied by increasing or decreasing the numberof light extracting regions within a predetermined area. In oneembodiment, the luminance of the light extraction region or lightextraction features is less than one selected from the group of 1, 5,10, 20, and 50 Cd/m² when viewed normal to the surface from the sidewith the light extraction features or the side without the lightextraction features with the light source not emitting light and under50 lux ambient illumination.

In one embodiment, the light emitting device is a sign with a lightemitting surface comprising at least one selected from the group oflight emitting regions, light extracting regions, and light extractionfeature which is not readily discernable by a person with a visualacuity between 0.5 and 1.5 arcminutes at a distance of 20 cm whenilluminated with 200 lux of diffuse light in front of Light AbsorbingBlack-Out Material from Edmund Optics Inc.

In another embodiment, the fill factor of the light extracting features,defined as the percentage of the area comprising light extractingfeatures in a square centimeter in a light emitting region, surface orlayer of the lightguide or film, is one selected from the group of lessthan 80%, less than 70%, less than 60%, less than 50%, less than 40%,less than 30%, less than 20%, and less than 10%. The fill factor can bemeasured within a full light emitting square centimeter surface regionor area of the lightguide or film (bounded by region is all directionswithin the plane of the lightguide which emit light) or it may be theaverage of the light emitting areas of the lightguides. The fill factormay be measured when the light emitting device is in the on state or inthe off state (not emitting light) where in the off state, the lightextracting features are defined as visual discontinuities seen by aperson with average visual acuity at a distance of less than 10 cm.

In another embodiment, the light emitting device is a sign with a lightemitting surface comprising light emitting regions wherein when thedevice is not emitting light, the angle subtended by two neighboringlight extracting features that are visible when the device is on, at adistance of 20 cm is less than one selected from the group of 0.001degrees, 0.002 degrees, 0.004 degrees, 0.008 degrees, 0.010 degrees,0.015 degrees, 0.0167 degrees, 0.02 degrees, 0.05 degrees, 0.08 degrees,0.1 degrees, 0.16 degrees, 0.2 degrees, 0.3 degrees, 0.4 degrees, 0.5degrees, 0.6 degrees, 0.7 degrees, 0.8 degrees, 1 degree, 2 degrees, and5 degrees. In another embodiment, the light emitting device is a signwith a light emitting surface comprising light emitting regions whereinwhen the device is not emitting light, the angle subtended by twoneighboring light extracting features (that are which are not easilyvisible when the device is off when illuminated with 200 lux of diffuselight) at a distance of 20 cm is less than one selected from the groupof 0.3 degrees, 0.4 degrees, 0.5 degrees, 0.6 degrees, 0.7 degrees, 0.8degrees, 1 degree, 2 degrees, and 5 degrees.

In a further embodiment, the light extraction features of the lightemitting device comprise light scattering domains of a material with adifferent refractive index than the surrounding material. In oneembodiment, the light scattering domain has a concentration within thecontinuous region having light scattering domains (such as an inkjetdeposited white ink pixel) less than one selected from the group of 50%,40%, 30%, 20%, 10%, 5%, 3%, 1%, 0.5%, and 0.1% by volume or weight. Theconcentration or thickness of the light scattering domains may vary inthe x, y, or z directions and the pixel or region may be overprinted toincrease the thickness. In another embodiment, the light extractingfeatures have a light absorbing region disposed between the lightextracting feature and at least one output surface of the light emittingdevice. For example, the light extracting features could be titaniumdioxide based white inkjet deposited pixels deposited on a lightguideand the light absorbing ink (such as a black dye or ink comprisingcarbon black particles) is deposited on top of the white ink such that50% of the light scattered from the white pixel is transmitted throughthe light absorbing ink. In this example, the ambient light that wouldhave reflected from the white ink if there were no light absorbing inkis reduced by 75% (twice passing through the 50% absorbing ink) and thevisibility of the dots is reduced while sufficient light from thelightguide is emitted from the light emitting device in the region nearthe white pixel. In another embodiment, a low light transmission, lightabsorbing material absorbing at least one selected from the group of 5%,10%, 20%, 30%, 40%, 50%, 60%, and 70% of the light emitted from a firstlight extracting feature is disposed between the light extractingfeature and at least one outer surface of the light emitting device.

In a further embodiment, the light extraction region is designed to besubstantially visible from only one side. In one embodiment, the lightextraction features are disposed on the non-viewing side of the lightemitting device between a low light transmission region and thelightguide. For example, in one embodiment, the light extraction regionsare printed white ink regions with light absorbing black ink overprintedon the white ink regions. In this embodiment, the white ink scatterslight out of the lightguide on the opposite side and a significantportion of the light transmitted through the white ink is absorbed bythe black ink. In another embodiment, the light extraction regionscomprise surface relief patterns on one side of a lightguide and a lowlight transmission film, such as a black PET film, is substantially cutin the shape of the extraction regions and disposed adjacent the lightextraction regions. In another embodiment, the low light transmissionregion does not conform to the shape of the light extraction regions.For example, in one embodiment, a light emitting device comprises alight source, lightguide, light input coupler, and a square black PETfilm is laminated to cladding layer which is laminated to a circularshaped logo pattern of white ink regions and the lightguide. In thisembodiment, the white ink pattern is visible from the side opposite theside of the lightguide comprising the black PET film and is notsubstantially visible from the side comprising the black PET film whenthe light source is turned on. In a further embodiment, the luminance ofthe light emitting display is less than one selected from the group of1, 5, 10, 20, and 50 Cd/m² when viewed normal to the surface from theside of the lightguide comprising the low light transmission film. In afurther embodiment, the luminance of the light emitting display isgreater than one selected from the group of 50, 75, 100, 200, and 300Cd/m² when viewed normal to the surface from the side of the lightguidecomprising the low light transmission film. In another embodiment, theluminance of the low light transmission region is less than one selectedfrom the group of 1, 5, 10, 20, and 50 Cd/m² when viewed normal to thesurface from the side of the lightguide comprising the low lighttransmission film with the light source not emitting light and under 50lux ambient illumination.

In another embodiment, the light extraction region comprising the lightextraction features is designed to be visible or legible from twoopposite directions. For example, in one embodiment, an image or graphicbased light extraction region is substantially symmetric such that it isvisually perceptible and correct when viewed from either side of awindow to which it is optically coupled or adjacent. In anotherembodiment, the light emitting device comprises two lightguides with alow light transmission region disposed in a region between thelightguides. In the previous embodiment, for example, a black polyesterfilm layer may be disposed between the lightguides (and between thecladding layers of the two lightguides) in the regions behind the lightextraction region in the form of readable text such there is a black oropaque background and the light emitting text is visible and easilylegible from either side. In one embodiment, the low light transmissionregion has an average transmittance across the wavelengths of lightemitted by the light emitting device less than one selected from thegroup of 70%, 60%, 50%, 40%, 30%, 20%, 10% and 5% measured bycollimating light from the light sources used in the light emittingdevice and measuring the total transmittance in the equipment setupprescribed in the ASTM D1003 standard.

In one embodiment, the thickness of the lightguide or core layer at thelight extraction feature in a first direction selected from the group ofperpendicular to the light emitting surface of the lightguide,perpendicular to the optical axis of the light within the lightguide atthe light extraction feature, and perpendicular to the direction oflight traveling in the lightguide at the light extraction featuredivided by the length of one or more light extraction features in afirst direction parallel to the direction of light traveling in thelightguide or parallel to the optical axis of the light within thelightguide is greater than one selected from the group of 1, 2, 5, 10,15, 20, and 50.

In one embodiment, the lightguide comprises a coating or layer disposedin optical contact with the lightguide comprising the light extractionfeatures. In one embodiment, for example, a UV curablemethacrylate-based coating is coated onto a silicone-based lightguideand is cured in when in contact with an embossing drum such that thelight extraction features are formed on the coating on thesilicone-based lightguide. Various UV curable coatings are suitable foruse in this embodiment, and the refractive index, light transmissionproperties, adhesion properties, and scattering properties are known inthe optical film industry.

In one embodiment, the lateral dimension of one or more light extractionfeatures in the light emitting region in a direction parallel to theoptical axis of the light within the lightguide at the light extractionfeature is less than one selected from the group of 1 mm, 500 microns,250 microns, 200 microns, 150 microns, 100 microns, 75 microns, 50microns, 25 microns, 20 microns, 10 microns, 5 microns, 2 microns, 1microns, 0.5 microns, and 0.3 microns. In another embodiment, theaverage lateral dimension of the light extraction features in the lightemitting region in a direction parallel to the optical axis of the lightwithin the lightguide at the light extraction feature is less than oneselected from the group of 1 mm, 500 microns, 250 microns, 200 microns,150 microns, 100 microns, 75 microns, 50 microns, 25 microns, 20microns, 10 microns, 5 microns, 2 microns, 1 microns, 0.5 microns, and0.3 microns. In another embodiment, the fill factor of the lightextracting features, defined as the percentage of the area comprisinglight extracting features in a square centimeter in a light emittingregion, surface or layer of the lightguide or film, is one selected fromthe group of less than 80%, less than 70%, less than 60%, less than 50%,less than 40%, less than 30%, less than 20%, and less than 10%. The fillfactor can be measured within a full light emitting square centimetersurface region or area of the lightguide or film (bounded by region isall directions within the plane of the lightguide which emit light) orit may be the average of the light emitting areas of the lightguides.The fill factor may be measured when the light emitting device is in theon state or in the off state (not emitting light) where in the offstate, the light extracting features are defined as visualdiscontinuities seen by a person with average visual acuity at adistance of less than 10 cm.

In a further embodiment, the light extraction region is designed to besubstantially visible from only one side. In one embodiment, the lightextraction features are disposed on the non-viewing side of the lightemitting device between a low light transmission region and thelightguide. For example, in one embodiment, the light extraction regionsare printed white ink regions with light absorbing black ink overprintedon the white ink regions. In this embodiment, the white ink scatterslight out of the lightguide on the opposite side and a significantportion of the light transmitted through the white ink is absorbed bythe black ink.

Visible Light Extraction Features Also Providing Illumination

In one embodiment, the light from the light extraction features providesillumination of an object or surface and the light extraction featuresprovide a visible pattern, logo, indicia or graphic. In one embodiment afirst percentage of light exiting the lightguide due to the lightextraction features illuminates a surface, object or region, and thesecond percentage of light exits the lightguide in a pattern, logo,indicia, or graphic and is visible directly. In another embodiment, afirst percentage of light exiting a light emitting device from the firstsurface of the lightguide illuminates a surface, object, or region and asecond percentage of light exits the light emitting device from thesecond surface of the lightguide opposite the first surface and thelight extraction features form a visible pattern, logo, indicia, orgraphic. For example, in one embodiment, a printed white ink lightextraction region on one side of a lightguide with a diffuse reflectanceof about 60% (measured from the air side and not through thelightguide), reflects a first percentage (approximately 30%) of incidentlight out of the lightguide toward a viewing side, transmitsapproximately 40% through the light extraction features out of thelightguide to illuminated a product in a POP display, and approximately30% of the reflected light remains within the lightguide.

Protective Layers

In one embodiment, at least one selected from the group of the lightinput surface, light input coupler, coupling lightguide, lightguideregion, and lightguide comprises a protective element or layer opticallycoupled to it, physically coupled to it, disposed adjacent to it, ordisposed between it and a light emitting surface of the light emittingdevice. A protective film element can have a higher scratch resistance,higher impact resistance, hardcoating layer, impact absorbing layer orother layer or element suitable to protect at least one selected fromthe group of light input surface, light input coupler, couplinglightguide, lightguide region, and lightguide from scratches, impacts,dropping the device, and interaction with sharp objects, etc. In anotherembodiment, at least one outer surface region of the lightguide (orlayer thereof) comprises a removable protective film or masking film.For example, in one embodiment, a film based lightguide comprisesremovable protective polyethylene films physically coupled to thecladding regions on either side of a core region. In another embodiment,one of the cladding regions is an adhesive and the protectivepolyethylene film prevents contamination of the adhesive before the filmis adhered to a window, for example, and the other cladding regioncomprises a “hardcoat” coating with a pencil hardness greater than 2Hwhere the protective polyethylene film prevents scratches beforeinstallation of the light emitting device.

Removable and Replaceable Light Extraction Region

In one embodiment, a light emitting device includes a light extractionregion that may be removed and replaced on a film-based lightguide orrepositioned on a film-based lightguide. In another embodiment, thelight extraction region is a film or component including lightextraction features that is physically and optically coupled to thelightguide such that light travels within the lightguide in a waveguidecondition and is extracted by the light extraction features in the lightextraction region. In another embodiment, the light extraction regionincludes light extraction surface features such that when the featuresare in contact with the film-based lightguide, a portion of the lightincident on the light extraction surface features is redirected into anangle such that light escapes the film-based lightguide. In anotherembodiment, the light extraction region on the film or component has aprotective region or film that can be removed prior to adhering thelight extraction region to the film-based lightguide. In anotherembodiment, the light extraction region is adhered to the film-basedlightguide using a low peel strength adhesive, static bond or other lowstrength bond. In one embodiment, the light extraction layer or regionhas an ASTM D 903 (modified for 72 hour dwell time) peel strength tostandard window glass less than one selected from the group of: 70oz/in, 50 oz/in, 40 oz/in, 30 oz/in, 20 oz/in and 10 oz/in. In anotherembodiment, the adhesive, when adhered to glass, will support the weightof the light emitting device. For example, the film-based lightguide maybe a polycarbonate film and the light extraction region may be a PVC orsilicone-based film that can be disposed onto the film-based lightguidesuch that the light extraction region extracts light from thelightguide. In another embodiment, a first light extraction region formsindicia from white ink light extraction features on a silicone-basedfilm. In this embodiment, the silicone-based film is removed by peelingthe silicone-based film away from a silicone film-based lightguide. Inthis embodiment, the first light extraction region is replaced with anew light extraction region including embossed features on the surfaceof a new silicone film with the features oriented toward the siliconefilm-based lightguide where the light extraction region includes a lowrefractive index protective cladding region, layer or film on theopposite side. In this embodiment, the surface light extraction featureson the light extraction region essentially become volumetric lightextraction features for the lightguide which is formed from thecombination of the silicone-based light extraction region and thesilicone film-based lightguide. In a further embodiment, the adhesivemay be removed from the two components to which the adhesive is designedto combine. For example, in one embodiment, the adhesive film orcomponent may be removed from window glass and a region of thelightguide. In another example, the adhesive film or component may beremoved from the light extraction region and the lightguide. In oneembodiment, the light extraction region maintains sufficient adhesionduring normal operation and can be removed permitting reuse of acomponent or region. For example, in one embodiment, the adhesive may beremoved (by peeling for example) from the lightguide film such that anew adhesive film may be used with the light extraction region to applythe light extraction region to another surface without dirt,contamination, or blemishes from the previous adhesion. In the previousexample, this could be advantageous when one wishes to change a lightemitting device window display using a film-based lightguide fromdisplaying a Thanksgiving holiday image in the light extraction film toa Christmas holiday image in a different light extraction film, forexample. In another embodiment, the adhesive layer, region, or materialmay be cleaned, such as washing in soap and water, for example) andreused to reapply the light extraction region to the lightguide.

In one embodiment, the light emitting device includes a cladding regionon the lightguide that may be removed or peeled back from the coreregion of the lightguide such that the light extraction region (or filmincluding light extraction features) may be added. In anotherembodiment, the light emitting device includes a lightguide opticallycoupled to a first light extraction region, and the first lightextraction region is peeled off and a second light extraction region isoptically coupled to the lightguide. In one embodiment, the claddinglayer is physically coupled to the housing or lightguide along one edgeor region such that when peeled back, the relative alignment andposition is maintained for reapplying the cladding layer. For example,in one embodiment, the cladding layer is bonded with a high strengthadhesive along the top end of a core region and is coupled to the regionbelow the top end of the lightguide by a low tack adhesive or adhesivewith low peel strength that enables the cladding layer to be readilypeeled back by hand.

In one embodiment, the light extraction region includes a lighttransmitting film with an arrangement of light extraction featuresdisposed within or upon a surface. In one embodiment, one or more of thelight extraction region, the core region, and the cladding layer hasadhesive properties. In another embodiment, the adhesive properties are“low tack” such as those typical with silicone, “static cling film”based on polyvinyl chloride with relatively high plasticizer content, oradhesives with low peel strength.

In another embodiment, the light extraction region is an ink or othersuitable transferable material that can be transferred onto thefilm-based lightguide. For example, a film including an ink pattern withan adhesive component could be transferred onto the film-basedlightguide by lamination or pressing the film against the film-basedlightguide. The carrier or transfer media supporting the transfermaterial or feature may be a film, plastic, metal or other flexible orrigid material. For example, the transfer material may be an embossedmetal plate that is pressed against the film-based lightguide totransfer a surface pattern from the metal to the film-based lightguideto create surface relief light extraction features. In anotherembodiment, the transfer material is a thin layer of a coating that canbe released from or physically bonded to the light extraction region orfeatures. In another embodiment, the light extraction region has acarrier film, layer or region that can be removed subsequent tooptically coupling the light extraction features to the film-basedlightguide or the light extraction region may remain physically coupledto the light extraction features. In one embodiment, the lightextraction region of the lightguide includes light extraction films of avariety of shapes and the light extraction features or light extractionregions including the light extraction features may also be a variety ofshapes to achieve a desired appearance or particular spatial or angularlight output profile from the light emitting device. In anotherembodiment, the light emitting device includes a plurality of lightextraction films or regions disposed to couple light out of thelightguide at specific locations or orientations that are predeterminedor user configurable or reconfigurable.

In another embodiment, a sign or display kit includes a light inputcoupler, a film-based lightguide and one or more light extraction filmssuch that the user may chose the particular light extraction region filmto dispose on the film-based lightguide. In another embodiment, thelight extraction film includes an alignment feature that indicates thecorrect side of the light extraction film to be optically coupled to thefilm-based lightguide. For example, a silicone light extraction filmincludes a printed ink pattern underneath a removable protective film onone side, a low refractive index cladding region on the opposite side,and a notch cut from one corner. The user is instructed (throughinstructions or diagrams for example) to peel away the protective filmsfrom the silicone film-based lightguide and the silicone lightextraction film and position the notch on the silicone light extractionfilm in the bottom left corner on the side of the silicone film-basedlightguide that is opposite the side of the light input coupler, forexample. Other alignment features or guides including printed inkspatterns, registration marks, grooves, apertures and/or holes, forexample, may be used.

In one embodiment, the light extraction region includes film surfacefeatures that substantially prevent optical coupling in first regions,and light coupling or light extraction regions that redirect light toangles not supported by the lightguide or transmit light to lightextraction regions. In one embodiment, the film surface features thatsubstantially prevent optical coupling are low contact area coverfeatures.

Multiple Lightguides

In one embodiment, a light emitting device includes more than onelightguide to provide one or more of the following: color sequentialdisplay, localized dimming backlight, red, green, and blue lightguides,animation effects, multiple messages of different colors, NVIS anddaylight mode backlight (one lightguide for NVIS, one lightguide fordaylight for example), tiled lightguides or backlights, and large arealight emitting devices comprised of smaller light emitting devices. Inanother embodiment, a light emitting device includes a plurality oflightguides optically coupled to each other. In another embodiment, atleast one lightguide or a component thereof includes a region withanti-blocking features such that the lightguides do not substantiallycouple light directly into each other due to touching.

Other Components

In one embodiment, the light emitting device includes one or more of thefollowing: a power supply, batteries (which may be aligned for a lowprofile or low volume device), a thermal transfer element (such as aheat sink, heat pipe, or stamped sheet metal heat sink), a frame, ahousing, a heat sink extruded and aligned such that the heat sinkextends parallel to at least one side of the lightguide, multiplefolding or holding modules along a thermal transfer element or heatsink, a thermal transfer element exposed to thermally couple heat to asurface external to the light emitting device, a solar cell capable ofproviding power, communication electronics (such as needed to controllight sources, color output, input information, remote communication,Wi-Fi control, Bluetooth® control, and/or wireless internet control, forexample), a magnet for temporarily affixing the light emitting device toa ferrous or suitable metallic surface, a motion sensor, a proximitysensor, forward and backwards oriented motion sensors, an opticalfeedback sensor (including photodiodes or LEDs employed in reverse asdetectors), controlling mechanisms such as switches, dials, keypads (forfunctions such as on/off, brightness, color, color temp, presets (forcolor, brightness, and/or color temp, for example), wireless control,externally triggered switches (door closing switch for example),synchronized switches, and light blocking elements to block externallight from reaching the lightguide or lightguide region or to blocklight emitted from a region of the light emitting device from being seenby a viewer. In one embodiment, the light emitting device is designed tobe powered by an automobile's electrical system or a 12 volt DC powerbattery or power supply. For example, in one embodiment, a light fixtureincludes a light source such as a linear array of LEDs directing lightupwards and a light input surface disposed to receive light propagatingwith a component upwards and direct the light through couplinglightguides to a light emitting region disposed on the underside of thelight fixture. In this embodiment, for example, a linear pendantluminaire can direct light upwards and provide illumination directlydownwards using the lightguide film and coupling lightguides. Similarly,a wall washing light fixture that directs light upwards may emit lighthorizontally or downwards using the coupling lightguides and lightguideto redirect an angular range of the light output of the light sourceinto the lightguide and out of the lightguide in a different angularrange.

Motion Sensor

In another embodiment, the light emitting device includes a motionsensor. Types of motion sensors include passive infrared sensors, activeinfrared sensors, ultrasonic motion sensors, and microwave motionsensors. In one embodiment, the motion sensor is disposed to receiveradiation passing through the film-based lightguide or from within thefilm-based lightguide (such as when exterior light is redirected intothe lightguide by the light extraction features and travels through thelightguide to reach the motion sensor). In another embodiment, movementdetected by the motion sensor triggers the light emitting device tochange the light output characteristics. In one embodiment, the lightemitting device has light emitting characteristics that change by one ormore of the following: emitting light in one or more light emittingregions, stopping emitting light in one or more light emitting regions,changing the overall light flux output (increase or decrease by anamount) in one or more light emitting regions, changing the angularlight output profile in one or more light emitting regions, changing thecolor of the light output in one or more light emitting regions. Forexample, in one embodiment, the motion sensor triggers the lightemitting device to turn on. In another example, the motion sensortriggers the light emitting device to pulse one LED off and on for aflashing logo in a first light emitting region while maintaining thelight output of a second LED at a constant visible light output level ina second light emitting region.

In another embodiment, the light input coupler is disposed to receivelight from a light source and transmit the light through couplinglightguide into a larger light emitting area such as to provide a lowerluminance level light output spread over a larger light emitting area.For example, in one embodiment, the light input coupler is disposed toreceive light directed upwards from a light source in a lamp and directthe light through coupling lightguides to the light emitting regiondisposed in the “lamp shade”. In this embodiment, the light istransmitted through the lightguide and exits the shade directly (inembodiments when the light emitting region is on the outer portion ofthe “lamp shade”) without being absorbed by travelling through the lightabsorbing material of the lamp shade. In this embodiment, the lightguidemay be disposed within, on the inner surface, or on the outer surface ofa lamp shade. In another embodiment, the lightguide provides lightdiffusing properties (such as a volumetric diffusion layer, surfacerelief diffusing layer, or printed diffuser layer) to reduce the glareof the light source and includes light emitting regions that receivelight from the light source through coupling lightguides.

In another embodiment, the light emitting device provides light outputin a shade or patterned region that is different that the light exitingout of a neighboring region. For example, in one embodiment, thefilm-based lightguide emits light in a green and red flower patternwhile the light transmitted through the shade (from a standard Edisontype incandescent light bulb disposed in the lamp, for example) is asecond color such as warm white. In one embodiment, a low lighttransmitting region is disposed between the light emitting region and alight emitting region of external light incident on the light emittingregion such that the saturation of the light emitted from the lightemitting region is increased. For example, in one embodiment, a tablelamp with an incandescent light source disposed within includes aluminous lamp shade of with a lightguide film disposed to receive lightfrom a blue LED and to emit blue light from white ink light extractionfeatures in the form of a blue logo and a black ink overprinted on thewhite ink light extraction features increases the color saturation overthe light extraction region without the low light transmitting region.

Other Optical Films

In another embodiment, the light emitting device further includes alight redirecting optical film, element, or region that redirects lightincident at a first range of angles, wavelength range, and polarizationrange into a second range of angles different than the first.

Light Reflecting Film

In another embodiment, a light emitting device includes a lightguidedisposed between a light reflecting film and the light emitting surfaceof the light emitting device. In one embodiment, the light reflectingfilm is a light reflecting optical element. For example, a whitereflective polyester film of at least the same size and shape of thelight emitting region may be disposed on the opposite side of thelightguide as the light emitting surface of the light emitting device orthe light reflecting region may conform to the size and shape of one orall of the light emitting regions, or the light reflecting region may beof a size or shape occupying a smaller area than the light emittingregion.

Light Absorbing Region or Layer

In one embodiment, at least one selected from the group of the cladding,adhesive, layer disposed between the lightguide and lightguide regionand the outer light emitting surface of the light emitting device,patterned region, printed region, and extruded region on one or moresurfaces or within the volume of the film comprises a light absorbingmaterial which absorbs a first portion of light in a first predeterminedwavelength range. In one embodiment, the light absorbing region or layeris optically coupled to a cladding region on one or more of thefollowing regions: the coupling lightguide regions, the light mixingregions and the light emitting regions. In this embodiment, the lightabsorbing region can absorb a first portion of the light within thecladding to which it is optically coupled. In one embodiment, the firstportion of the light absorbed is greater than one selected from thegroup of 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 95%. In oneembodiment, the light traveling in the cladding is substantiallyabsorbed by the light absorbing region. In another embodiment, a lightscattering region or layer is optically coupled to or forms the outersurface of a region of the cladding in one or more of the followingregions: a coupling lightguide region, a light mixing region, and alight emitting region. In this embodiment, the light traveling withinthe cladding can be extracted substantially before the light emittingregion (or an area of interest in the light emitting region) byscattering it out of the cladding region. Removing the light travelingwithin the cladding, for example, may be desired in frontlightapplications where fingerprints, smudges, oil, residue, dust, andscratches in the cladding or outer surface may be illuminated or visibledue to the light traveling within the cladding.

In one embodiment, the first predetermined wavelength range includeslight from 300 nm to 400 nm and the region absorbs UV light that coulddegrade or yellow the lightguide region, layer or other region or layer.In one embodiment, the cladding region is disposed between the lightabsorbing region and the lightguide such that the light travelingthrough the lightguide and the evanescent portion of the lighttravelling within the lightguide is not absorbed due to the absorbingregion since it does not pass through the absorbing region unless it isextracted from the lightguide. In another embodiment, the lightabsorbing region or layer is an arrangement of light absorbing, lightfluorescing, or light reflecting and absorbing regions which selectivelyabsorb light in a predetermine pattern to provide a light emittingdevice with spatially varying luminance or color (such as in adye-sublimated or inject printed overlay which is laminated or printedonto a layer of the film to provide a colored image, graphic, logo orindicia). In another embodiment, the light absorbing region is disposedin close proximity to the light extracting region such that the lightemitted from the light emitting device due to the particular lightextraction feature has a predetermined color or luminous intensity. Forexample, inks comprising titanium dioxide and light absorbing dyes canbe disposed on the lightguide regions such that a portion of the lightreaching the surface of the lightguide in that region passes through thedye and is extracted due to the light extraction feature or the light isextracted by the light extraction feature and passes through the dye.

In one embodiment, a light emitting device comprises a five layerlightguide region with a UV light absorbing material disposed in theouter layers which are both optically coupled to cladding layers whichare both optically coupled to the inner lightguide layer. In oneembodiment, a 5 layer film comprises a polycarbonate material in thecentral lightguide layer with low refractive index cladding layers of athickness between 1 micron and 150 microns optically coupled to thelightguide layer and a UV light absorbing material in the outer layersof the film.

In another embodiment, a light absorbing material is disposed on oneside of the light emitting device such that the light emitted from thedevice is contrasted spatially against a darker background. In oneembodiment, a black PET layer or region is disposed in proximity to oneside or region of the light emitting device. In another embodiment,white reflecting regions are disposed in proximity to the lightextracting region such that the light escaping the lightguide in thedirection of the white reflecting region is reflected back toward thelightguide. In one embodiment, a lightguide comprises a lightguideregion and a cladding region and a light absorbing layer is disposed(laminated, coated, co-extruded, etc.) on the cladding region. In oneembodiment, light from a laser cuts (or ablates) regions in the lightabsorbing layer and creates light extracting regions in the claddingregion and/or lightguide region. A white reflecting film such as a whitePET film with voids is disposed next to the light absorbing region. Thewhite film may be laminated or spaced by an air gap, adhesive or othermaterial. In this example, a portion of the light extracted in the lightextracting regions formed by the laser is directed toward the white filmand reflected back through the lightguide where a portion of this lightescapes the lightguide on the opposite side and increases the luminanceof the region. This example illustrates an example where registration ofthe white reflecting region, black reflection region, and lightextracting regions are not necessary since the laser created holes inthe black film and created the light extracting features at the sametime. This example also illustrates the ability for the light emittingdevice to display an image, logo, or indicia in the off state wherelight is not emitted from the light source since the white reflectiveregions reflect ambient light. This is useful, for example, in a signapplication where power can be saved during the daytime since ambientlight can be used to illuminate the sign. The light absorbing region orlayer may also be a colored other than black such as red, green, blue,yellow, cyan, magenta, etc.

In another embodiment, the light absorbing region or layer is a portionof another element of the light emitting device. In one embodiment, thelight absorbing region is a portion of the black housing comprising atleast a portion of the input coupler that is optically coupled to thecladding region using an adhesive.

In another embodiment, the cladding, outer surface or portion of thelightguide of a light emitting device comprises a light absorbing regionsuch as a black stripe region that absorbs more than one selected fromthe group of 50%, 60%, 70%, 80% and 90% of the visible light travelingwithin the cladding region. In one embodiment, the light absorbingregion absorbs light traveling within the cladding region from lightcoupled into the cladding region at the light input surface of thecoupling lightguides in the light input coupler. In another embodiment,the lightguide is less than 200 microns in thickness and a lightabsorbing region optically coupled to the cladding absorbs more than 70%of the light traveling within the cladding which passes through thelightguide passing the light absorbing region, wherein the thickness ofthe cladding in the direction of the light traveling within thelightguide is less than one selected from the group of 10 millimeters, 5millimeters, 3 millimeters, 2 millimeters, and 1 millimeter. In anotherembodiment, the light absorbing region has a width in the direction ofpropagation of light within the lightguide between one selected from thegroup of 0.5-3 millimeters, 0.5-6 millimeters, and 0.5-12 millimeters.

In one embodiment, the light absorbing region is at least one selectedfrom the group of a black line, a patterned line, a pattern shape orcollection of shapes, patterned on one or both sides of the film,cladding, or layer optically coupled to the cladding, patterned on oneor more lightguide couplers, patterned in the light mixing region,patterned in the lightguide, and patterned in the lightguide region. Inanother embodiment, the light absorbing region is patterned during thecutting step for the film, coupling lightguides, or cutting step ofother regions, layers or elements. In another embodiment, the lightabsorbing region covers at least one percentage of surface area of thecoupling lightguides selected from the group of 1%, 2%, 5%, 10%, 20%,and 40%.

In one embodiment, one or more of the cladding, the adhesive, the layerdisposed between the lightguide and lightguide region and the outerlight emitting surface of the light emitting device, a patterned region,a printed region, and an extruded region on one or more surfaces orwithin a volume of the film includes a light absorbing material whichabsorbs a first portion of light in a first predetermined wavelengthrange.

Adhesion Properties of the Lightguide, Film, Cladding or Other Layer

In one embodiment, one or more of the lightguide, the core material, thelight transmitting film, the cladding material, and a layer disposed incontact with a layer of the film has adhesive properties or includes amaterial with one or more of the following: chemical adhesion,dispersive adhesion, electrostatic adhesion, diffusive adhesion, andmechanical adhesion to at least one element of the light emitting device(such as a carrier film with a coating, an optical film, the rearpolarizer in an LCD, a brightness enhancing film, another region of thelightguide, a coupling lightguide, a thermal transfer element such as athin sheet comprising aluminum, or a white reflector film) or an elementexternal to the light emitting device such as a window, wall, orceiling. In one embodiment, the cladding is a “low tack” adhesive thatallows the film to be removed from a window or substantially planarsurface while “wetting out” the interface. By “wetting out” theinterface as used herein, the two surfaces are optically coupled suchthat the Fresnel reflection from the interfaces at the surface is lessthan 2%. The adhesive layer or region may include one or more of thefollowing: pressure sensitive adhesive, contact adhesive, hot adhesive,drying adhesive, multi-part reactive adhesive, one-part reactiveadhesive, natural adhesive, synthetic adhesive, polyacrylate adhesive,animal glue or adhesive, carbohydrate polymer as an adhesive, naturalrubber based adhesive, polysulfide adhesive, tannin based adhesive,lignin based adhesive, furan based adhesive, urea formaldehyde adhesive,melamine formaldehyde adhesive, isocyanate wood binder, polyurethaneadhesive, polyvinyl and ethylene vinyl acetate, hot melt adhesive,reactive acrylic adhesive, anaerobic adhesive, and epoxy resin adhesive.In one embodiment, the adhesive layer or region has an ASTM D 903(modified for 72 hour dwell time) peel strength to standard window glassless than one selected from the group of: 70 oz/in, 50 oz/in, 40 oz/in,30 oz/in, 20 oz/in and 10 oz/in. In another embodiment, the adhesive,when adhered to glass, will support the weight of the light emittingdevice. In another embodiment, the adhesive material has an ASTM D3330peel strength greater than one selected from the group of: 0.5, 1, 2, 3,4, 5, 6, 7, 8, 9, and 10 pounds per inch width when adhered to anelement of the light emitting device, such as for example, a claddinglayer, a core layer, a low contact area cover, a circuit board, or ahousing or when adhered to glass or other component or device externalto the light emitting device.

Light Redirecting Element Disposed to Redirect Light from the Lightguide

In one embodiment, a light redirecting element redirects a portion oflight of a first wavelength range incident in a first angular range intoa second angular range different than the first. In one embodiment, thelight redirecting element include at least one surface or volumetricelement or feature selected from the group of: refractive, prismatic,totally internally reflective, specular reflective element or coating,diffusely reflective element or coating, reflective diffractive opticalelement, transmissive diffractive optical element, reflectiveholographic optical element, transmissive holographic optical element,reflective light scattering, transmissive light scattering, lightdiffusing, multi-layer anti-reflection coating, moth-eye orsubstantially conical surface structure type anti-reflection coating,Giant Birefringent Optic multilayer reflection, specularly reflectivepolarizer, diffusely reflective polarizer, cholesteric polarizer, guidedmode resonance reflective polarizer, absorptive polarizer, transmissiveanisotropic scattering (surface or volume), reflective anisotropicscattering (surface or volume), substantially symmetric or isotropicscattering, birefringent, optical retardation, wavelength converting,collimating, light redirecting, spatial filtering, angular dependentscattering, electro-optical (PDLC, liquid crystal, etc.),electrowetting, electrophoretic, wavelength range absorptive filter,wavelength range reflective filter, structured nano-feature surface,light management components, prismatic structured surface components,and hybrids of two or more of the aforementioned films or components. Ina further embodiment, the light redirecting element includes a pluralityof the aforementioned elements. The plurality of elements may be in theform of a 2-D array (such as a grid of microlenses or close-packed arrayof microlenses), a one-dimensional array (such as a lenticular lensarray), random arrangement, predetermined non-regular spacing,semi-random arrangement, or other predetermined arrangement. Theelements may include different features, with different surface orvolumetric features or interfaces and may be disposed at differentthicknesses within the volume of the light redirecting element,lightguide, or lightguide region. The individual elements may vary inthe x, y, or z direction by one or more of the following: height, width,thickness, position, angle, radius of curvature, pitch, orientation,spacing, cross-sectional profile, and location in the x, y, or z axis.

In one embodiment, the light redirecting optical element is disposedbetween at least one region of the light emitting region and the outersurface of the light emitting device (which may be a surface of thelight redirecting optical element). In one embodiment, a light emittingdevice includes a lightguide with light redirecting elements disposed onand/or within the lightguide and light extraction features disposed in apredetermined relationship relative to one or more light redirectingelements. In another embodiment, a first portion of the lightredirecting elements are disposed above a light extraction feature in adirection substantially perpendicular to the light emitting surface,lightguide, or lightguide region. In one embodiment, the lightguideincludes a substantially linear array of lenticules disposed on at leastone surface opposite a substantially linear array of light extractionfeatures wherein the light redirecting element collimates a firstportion of the light extracted from the lightguide by the lightextraction features. Examples of light redirecting optical elements inthe form of films with prismatic structured surfaces include, but arenot limited to, Vikuiti™ Brightness Enhancement Film (BEF I, BEF II, BEFIII, BEF III 90/50 5T, BEF III 90/50 M, BEF III 90/50 M2, BEF III 90/507T, BEF III 90/50 10T, BEF III 90/50 AS), Vikuiti™ Transparent RightAngle Film (TRAF), Vikuiti™ Optical Lighting Film (OLF or SOLF), IDF II,TRAF II, or 3M™ Diamond Grade™ Sheeting, all of which are available from3M Company, St. Paul, Minn. Other examples of light management componentconstructions may include the rounded peak/valley films described inU.S. Pat. Nos. 5,394,255 and 5,552,907 (both to Yokota et al.), ReversePrism Film from Mitsubishi Rayon Co., Ltd or other totally internallyreflection based prismatic film such as disclosed in U.S. Pat. Nos.6,746,130, 6,151,169, 5,126,882, and 6,545,827, lenticular lens arrayfilm, microlens array film, diffuser film, microstructure BEF,nanostructure BEF, Rowlux® microlens film from Rowland Technologies,films with arrangements of light concentrators such as disclosed in U.S.Pat. No. 7,160,017, and hybrids of one or more of the aforementionedfilms.

Off-Axis Light Redirection

In a further embodiment, at least one light extraction feature iscentered in a first plane off-axis from an axis of a light redirectingelement. In this embodiment, a portion of the light extraction featuremay intersect an optical axis of the light extraction feature or thelight extraction feature may be disposed sufficiently far from theoptical axis that the light extraction feature does not intersect theoptical axis of the light extraction feature. In another embodiment, thedistance between the centers of the light extraction features and thecorresponding light redirecting elements in first plane varies across anarray or arrangement of light redirecting elements.

Flexible Light Emitting Device, Backlight, or Frontlight

In another embodiment, a light emitting device, such as a display,includes a film-based light emitting device including a light source,light input coupler, and lightguide wherein the lightguide, lightguideregion, or coupling lightguides can be bent or folded to radius ofcurvature of less than 75 times the thickness of lightguide orlightguide region and function similarly to similar lightguide orlightguide region that has not been similarly bent. In one embodiment,the light emitting device or display incorporating the light emittingdevice has a light emitting surface area substantially in the shape ofor including a portion of a shape of one or more or the following: acylinder, sphere, pyramid, torus, cone, arcuate surface, folded surface,and bent surface. By folding the input coupler behind the light emittingregion and inside a curved or bent region of the light emitting deviceor display, the input coupler can be effectively “hidden” from view anda substantially seamless display or light fixture can be created. Inanother embodiment, two or more regions of a light emitting region in alight emitting device overlap each other in the thickness direction suchthat there is a continuous light emitting region such as in the case ofa cylindrical light emitting device or a light emitting device wrappingaround two or more sides of a rectangular solid.

Point of Purchase Display

In one embodiment, a light emitting point of purchase (POP) displayincludes a film-based lightguide, coupling lightguides, and a lightinput coupler. In another embodiment, the point of purchase display is ashelving system with tags, indicators, indicia, graphics, or othermedia. In another embodiment, the POP display includes a light emittingdevice electrically connected to a motion sensor. In one embodiment, thelight emitting device is integrated into the POP display such that oneor more regions of the POP display have light emitting indicia (such asa logo, graphic, text, symbol, or picture). In another embodiment, thelightguide has one or more substantially transparent regions and isdisposed in front of a region of the point of purchase display. Forexample, in one embodiment, a POP display comprises a printed cardboardregion with a substantially transparent lightguide disposed above it. Inthis embodiment, the red printed cardboard region is visible through thelightguide when the light emitting device is not emitting light and isvisible in non-light emitting regions of the lightguide when the lightemitting device is emitting light. In one embodiment, the lightguide isdisposed over text regions, graphic regions, uniform colored regions(red or white background for example) or other printed or unprintedregions of the display. In one embodiment, the light emitting region isused to enhance the printed region. For example, in one embodiment, thelight emitting region emits red light in the form of indicia spelling“SALE” and is disposed above a similar size and shape printed region ofthe POP display spelling “SALE”. In another embodiment, the lightemitting region emits light that at least one selected from the group ofenhances edges, outlines shapes or printed indicia, and indicates aparticular product within or region of the POP display. In anotherembodiment, the light emitting region of a lightguide in a first outputregion is disposed above a printed region of a display or sign that hasa diffuse reflectance less than one selected from the group of 60%, 50%,40%, 30%, 20%, 10%, and 5%. For example, in one embodiment, a lightemitting device comprises a white light emitting region on a lightguideabove a black printed region such that the luminance contrast ratio ofthe light emitting region is high.

In one embodiment, the light emitting device is a point of purchasedisplay including a light input coupler and lightguide disposed to beextended from the base of the display to a second region away from thedisplay. For example, in one embodiment, a light emitting point ofpurchase display includes a light input coupler disposed in a supportstructure or surface, such as in the ceiling of a store with afilm-based lightguide extending from the ceiling to the display base andthe film-based lightguide is substantially transparent between theceiling and the display base. In one embodiment, the light exiting thepoint of purchase display exits the film-based lightguide from a lightemitting region. In another embodiment, the light exiting the point ofpurchase display exits the film-based lightguide through output couplinglightguides disposed to emit light through light emitting regions. Inthis embodiment, for example, the light output couplers of the lightemitting device may be reconfigured or replaced to change the lightemitting properties of the display without needing to change thefilm-based lightguide functioning as a distribution lightguide extendingfrom the ceiling to the display base.

Illumination Device

In one embodiment, the light emitting device provides illumination. Inanother embodiment, the light emitting device includes a light sourceand a light emitting film or film-based lightguide wherein the lightemitting device is a light fixture, can light, troffer light, covelight, recessed light, torch lamp, floor lamp, chandelier, surfacemounted light, pendant light, sconce, track light, under-cabinet light,emergency light, wall-socket light, exit light, high bay light, low baylight, strip light, garden light, landscape light, building light,outdoor light, street light, pathway light, bollard light, yard light,accent light, background light, black light, flood light, safelight,safety lamp, searchlight, security light, step light, strobe light,follow-spot light, or wall-washer light, flashlight, wall light, ceilinglight, ceiling fan light, window light, door light, floor light, carlight, or vehicle light. In some embodiments, the types of illuminationdevice are not limited to traditional light fixtures or light sourcecategories and embodiments include light emitting devices that are thin,flexible, lightweight, substantially transparent, made ofnon-traditional materials can enable new categories or types ofillumination devices. For example, in one embodiment, a light emittingdevice including a thin substantially transparent film-based lightguidethat emits light may be disposed on a wall such that the light emittingdevice emits light from uniform or patterned light emitting regions inthe luminous state, and the film-based lightguide is substantially notvisible in the off state due to low absorption or high transmittance. Inanother embodiment, the light emitting device can be adhered, physicallycoupled to or disposed adjacent one or more surfaces of a wall, vehicle,floor, ceiling, mirror, window, glass surface, door, metal surface,polymer surface, curved surface, roughened or low gloss surface, or flatsurface. For example, in one embodiment, a film-based light emittingdevice includes an adhesive such that the film region, the light inputcoupler, or both can be applied to a wall or ceiling and the adhesivesupports the weight. In another example, the light emitting deviceincludes a wallpaper adhesive or wallpaper paste such as methylcellulose, modified starch base, wheat paste, pre-mixed vinyl clay,pre-mixed vinyl clear, for example. In another embodiment, the lightemitting device includes a paper layer. In this embodiment, a wallpaperpaste or adhesive may be used to adhere the light emitting region of thefilm, the film, or the light emitting device by allowing the adhesive tosoak into the paper layer. For example, in one embodiment, a lightemitting device includes a paper, board, or cellulose based layerdisposed on one side of a light emitting region of a lightguide disposedto receive light from the lightguide and reflect or absorb a portion ofthe incident light such that the light emitting region has an increasedluminance or increased image contrast from the opposite, viewing sideand the layer can be adhered to a surface using a wallpaper adhesive orwallpaper paste. In another embodiment, the paper, board, or cellulosebased layer providing light reflection or absorption is white,translucent, black, gray, or colored. In another embodiment, the lightemitting device has a peel-off liner that can be removed to expose anadhesive layer for application of a region of the lightguide to asurface.

In other embodiment, the light emitting device may be luminous in the onstate and substantially invisible in the off-state in the light emittingregion. In one embodiment, the light emitting surface includes lightemitting regions that are non-uniform and provide a visible pattern,image, logo, indicia, luminous accent lines corresponding to the edge ofthe lightguide, transparent windows for viewing through the lightguide,user-configurable or predetermined light output profiles, and/orreconfigurable or replaceable light output patterns or regions. In oneembodiment, the light emitting device includes a film-based lightguidethat can be positioned beneath a ceiling tile or panel with light sourcedisposed above the ceiling tile. For example, in one embodiment, a lightinput coupler is disposed above the tiles in a drop ceiling and a thinfilm-based lightguide is wrapped underneath a ceiling tile. In thisembodiment, the film-based lightguide maintains the continuity ofappearance of the ceiling while allowing light to be emitted fromregions of the light emitting film-based lightguide. The film may besufficiently thin to be positioned between the tile and the railingsupporting the tile. In one embodiment the film-based lightguide passesbetween the tile and a railing on one side of a tile and passes thoughthe tile and railing on the opposite side. In this embodiment, thefilm-based lightguide (and thus light emitting region of the film-basedlightguide and angular light output profile) may be adjusted to betaught under tension due to the weight or force between the tile andrail or it may be disposed to drape downward in an arcuate manner. Inanother embodiment, the film-based lightguide includes adhesive regionsdisposed on one or more sides to allow for the film to adhere to asurface such as a ceiling tile or wall. In a further embodiment, thefilm-based lightguide is substantially transparent in the off-state andthe tile, wall, ceiling or other surface seen through the lightguideappears substantially the same as the neighboring surface seen withoutlooking through the film-based lightguide. In another embodiment, thelight emitting device includes one or more organic light emitting diodes(OLEDs) on a flexible substrate. In this embodiment, the flexible OLEDis a light emitting film.

Reconfigurable Light Output Region

In one embodiment, the light emitting device includes a film-basedlightguide with a reconfigurable region. In one embodiment, the lightemitting device includes a lightguide or light emitting film that isplastically deformable such that the position and/or angle oforientation of one or more surface regions may be reconfigured. In oneembodiment, the lightguide or light emitting film may be reconfigured byhand without the use of tools. In one embodiment, the lightguide (orlight emitting film) or a plastically deformable material physicallycoupled to the lightguide (or light emitting film) has one or moreregions with a yield strength less than one selected from the group of:700 psi, 500 psi, 300 psi, 200 psi, and 100 psi. In another embodiment,the plastically deformable material may be deformed by at least oneselected from the group of: 50, 40, 30, 20, and 10 degrees withoutfracture. For example, in one embodiment, the light emitting deviceincludes a lightguide or light emitting film with a plasticallydeformable material that may be bent to form a new shape such as a thinaluminum sheet physically coupled to a white reflecting film that isphysically coupled to a cladding region of film-based lightguide (orlight emitting film). In this embodiment, the shape or orientation ofone or more regions of the lightguide or light emitting film may beadjusted to achieve a desired result (such as redirection of the lightoutput). In another embodiment, the light reflecting element is aplastically deformable light reflecting element.

In one embodiment, a light emitting device includes a film-basedlightguide or light emitting film wherein the shape of one or moreregions of the lightguide or light emitting film can be changed from asubstantially planar shape to a curved, arcuate, bent or wrinkled shapeand the light output profile is changed. For example, in one embodiment,a substantially planar light emitting region on a substantially planarfilm-based lightguide is folded such that the lateral dimension of thelightguide is reduced (for example, with a shape similar to a handheldpaper fan) and the angular full-width at half maximum luminous intensityin the output plane including the lateral dimension is increased.

In one embodiment, the light emitting region of the film-basedlightguide or light emitting film has a surface region with a surfaceangle relative to a reference direction that varies across the lightemitting region. The surface angle is the angle of the plane includingthe surface in the region relative to a reference direction. The averagesurface angle of the light emitting region is the average of the surfaceangles over all light emitting regions. For example, a light emittingdevice including a flat, planar lightguide with light emitting regionson the surface disposed parallel to a reference direction has an averagesurface angle of 0 degrees from the reference direction. In anotherexample, a light emitting device includes a film-based lightguide with asinusoidal light emitting region disposed continuously across thelightguide film surface with the reference direction parallel to thehorizontal axis of lightguide film and in the direction of light travel(with the sinusoid running horizontally) has an average surface angle ofthe light emitting region of 0 degrees from the reference direction dueto the averaging of the positive and negative sloped surfaces. Inanother embodiment the film-based lightguide or light emitting filmincludes light emitting regions only on the surface regions withpositive slopes on the sinusoidal shaped lightguide or light emittingfilm and the average surface angle of the light emitting regions may be,for example, +45 degrees from the reference direction. In anothersimilar embodiment, where the film-based lightguide or light emittingfilm includes light emitting regions only near the peak regions of thesinusoidal shaped lightguide or light emitting film, the average surfaceangle of the light emitting regions may be, for example, 0 degrees fromthe reference direction.

Bendable or Rotatable Light Emitting Panels

In one embodiment, the light emitting device includes a plurality oflightguides or light emitting film regions that may be repeatedly bentor rotated substantially independently such that the light outputprofile can be changed. In another embodiment, the light emitting deviceincludes a plurality of light input couplers and film-based lightguidesor light emitting films that may be rotated, bent or repositioned suchthat the angular light output profile of the light emitting device ischanged. For example, in one embodiment, a light emitting deviceincludes four light emitting panels disposed along the four edges of asquare panel. In one embodiment, the light emitting panels include lightinput couplers and film-based lightguides or light emitting films thatmay be independently rotated downward or upwards to change the lightemitting profile. In this embodiment, the central square panel includesa light emitting film-based lightguide disposed to receive light from aseparate light input coupler. In one embodiment, more than one lightpanel may receive light from the same light input coupler or lightsource. In another embodiment, all of the light emitting panels receivelight from the same light source. In some embodiments, the lightemitting panels include a rigid support on the light emitting side ofthe film-based lightguide (or light emitting film) or on the oppositeside of the lightguide (or light emitting film). In one embodiment, therigid support is substantially transparent in the region adjacent thelight emitting region of the lightguide or light emitting film. Inanother embodiment, the rigid support is substantially white, gray orspecular “mirror-like” in the region disposed adjacent the lightemitting region of the film-based lightguide or light emitting film suchthat it reflects light back through it. In another embodiment, one ormore rotatable, repositionable, or substantially stationary lightemitting panels are substantially rectangular, square, circular,semicircular, triangular, shaped such that they include curved regions,shaped such that they include linear regions, trapezoidal, polygonal,wave-like, shaped like strips, elliptical, enclosed shapes, orun-enclosed shapes (such as a shape of flat washer).

Lightguide or Light Emitting Film Adjustment Mechanism

In one embodiment, the light emitting device includes a film adjustmentmechanism for reconfiguring the shape or location of one or more regionsof a lightguide or light emitting film. In one embodiment, the filmadjustment mechanism is physically coupled to the lightguide or lightemitting film (such as adhered, clamped, or bonded). In anotherembodiment, one or more components of the film adjustment mechanism arein physical contact with one or more regions of the lightguide or lightemitting film in a first configuration and may be translated or rotatedaway from the point of contact with the lightguide or light emittingfilm in a second configuration. In one embodiment, the film adjustmentmechanism includes a plastically deformable material having at least oneregion with a yield strength less than one selected from the group of:700 psi, 500 psi, 300 psi, 200 psi, and 100 psi. In another embodiment,the yield strength is greater than one selected from the group of: 5psi, 10 psi, 20 psi, 40 psi, 50 psi, 70 psi and 100 psi. In anotherembodiment, the plastically deformable material of the film adjustmentmechanism may be deformed by at least one selected from the group of:50, 40, 30, 20, and 10 degrees without fracture. In another embodiment,the film adjustment mechanism includes one or more rails, wires, frames,supports, guides, rollers, bars, covers, lenses, and/or housingelements, that may be adjusted and repositioned without bending. In oneembodiment, the film adjustment mechanism provides support for one ormore of the following: a first light input coupler, a second light inputcoupler, lightguide or light emitting film positioning elements or rods,rail couplers, housing components, power supplies, and other componentsof a light emitting device. In another embodiment, the film adjustmentmechanism (such as a rail, tube, or guide, for example withoutlimitation) includes the electrical wiring or electrical connectionmeans for providing power to one or more light sources or a runner thatelectrically moves a region of the lightguide, light emitting film, orlight emitting device.

Bendable Side Support Rails

In one embodiment, the light emitting device includes a film adjustmentmechanism in the form of support rails for a region of the lightguide orlight emitting film that can be curved, bent or re-configured to changethe shape of the lightguide. The lightguide or light emitting film inmay remain or become taught or it may remain or be allowed to relax ordrape under low tension.

Bendable Mesh Support

In one embodiment, the lightguide or light emitting film includes a filmadjustment mechanism in the form of a bendable, plastically deformablemesh physically coupled to one or more regions of the lightguide orlight emitting film. In this embodiment, the lightguide (or lightemitting film) and mesh may be bent in a region such that the region hasa different shape or location relative to other regions of thelightguide, light emitting film, or light emitting device. In oneembodiment, the mesh includes an arrangement (such as matrix) of metalrods or tubes with combined yield strength less than one selected fromthe group of: 700 psi, 500 psi, 300 psi, 200 psi, and 100 psi in atleast one direction for at least one region. In another embodiment, theyield strength of the lightguide, light emitting film, or plasticallydeformable material is anisotropic and has yield strength in a firstdirection parallel to the lightguide or light emitting film surface anda second yield strength greater than the first yield strength in asecond direction parallel to the surface of the lightguide or lightemitting film and orthogonal to the first direction. For example, in oneembodiment, a light emitting device includes a lightguide or lightemitting film physically coupled to a plastically deformable wire meshwith a shorter pitch (or more wire) in first direction than in a seconddirection orthogonal to the first direction and the yield strength inthe first direction (or in a direction within the plane comprising thefirst direction) is greater than the yield strength in the seconddirection. In one embodiment, the light emitting device includes one ormore of the following: mesh disposed within a film or material, meshincluding one or more layers between the mesh and lightguide or lightemitting film, mesh including one or more materials on the opposite sideof the mesh than the lightguide or light emitting film, and mesh withone or more materials within the mesh. For example, in one embodiment,the mesh includes a flexible adhesive or polymer component within themesh grooves.

In one embodiment, a light emitting device includes a film adjustmentmechanism in the form of a plastically deformable mesh support includingwires that are physically attached at the intersection (such as weldingjoints) or the mesh may be interleaved. In another embodiment, the meshwires in one direction thread through holes in the wires in the otherdirection. In a further embodiment, the wire mesh is twisted around theintersecting wire mesh, such as in the case with common galvanized steel“chicken wire.” In another embodiment, the wire is embedded within, orsandwiched between two elements such as light reflecting films. In afurther embodiment, the wire is chrome plated such that the reflectancefrom the wire is greater than one selected from the group of: 50%, 60%,70%, 80% and 90%.

Adjustable Extension Guide

In one embodiment, the lightguide or light emitting film adjustmentmechanism is an adjustable extension guide including two components thatmay be brought closer together or separated further apart substantiallyalong a first direction. For example, in one embodiment, a lightemitting device includes two light input couplers on opposite sides of afilm-based lightguide or light emitting film wherein the light inputcouplers are physically connected by two slide extensions and can bepulled closer together or further apart. In this embodiment, the arc orradius of curvature of the film-based lightguide may be changed bybringing the light input couplers closer together or further apart.Additionally, in this embodiment, the arc or radius may be positive ornegative, pointing upwards or downwards, resulting in different angularlight output profiles for the light emitting device.

In one embodiment, the adjustable extension guide includes adjustablerails, a telescoping cylinder or similar telescoping device, a slidingrail, extension telescopic slides, a bearing slide, a linear-motionbearing, a roller slide, a dovetail slide, a plain bearing, a rollingelement bearing, a jewel bearing, a fluid bearing, a magnetic bearing,and a flexure bearing. In another embodiment, the film adjustmentmechanism is an adjustable extension guide including two components thatmay be brought closer together or separated further apart in one or moreregions along an arc or non-linear direction. For example, in oneembodiment, one region of a lightguide is physically coupled to thelight input coupler and a second region is physically coupled to a hingesuch that the orientation of the lightguide in the second region may berotated along a curve relative to the first region. In one embodiment,film adjustment mechanism is a hinge, such as a barrel hinge, a pivothinge, a Butt/Mortise hinge, a continuous hinge, a piano hinge, aconcealed hinge, a euro/cup hinge, a butterfly hinges, a parliamenthinge, a dovetail hinge, a strap hinge, an H hinge, an HL hinge, acounterflap hinge, a flush hinge, a coach hinge, a rising Butt hinge, adouble action spring hinge, a tee hinge, a friction hinge, a securityhinge, a cranked hinge, a stormproof hinge, a lift-off hinge, aself-closing hinge, building access hinges, a Butler tray hinge, a cardtable hinge, a drop leaf table hinge, and a long hinge.

Lightguide or Light Emitting Film Positioning Element

In one embodiment, the light emitting device includes one or morelightguide or light emitting film positioning elements disposed tocontact one or more regions of the film-based lightguide or lightemitting film. In another embodiment, the light emitting device includeslightguide or light emitting film positioning elements disposedsubstantially opposite each other on opposite sides of a film-basedlightguide or light emitting film. In this embodiment, the lightguide orlight emitting film positioning elements may be adjusted to applypressure on the lightguide or light emitting film to substantiallymaintain the location of the particular region of the lightguide betweenthe rods. Thus, by clamping or holding by pressure the lightguide orlight emitting film in a location, the form or shape may be adjusted andbe substantially held in that location until purposefully altered. Forexample, in one embodiment, a light emitting device includes a lightinput coupler on one side of film-based lightguide and a rail coupler onthe opposite side of the film-based lightguide. Guide rails disposedparallel to the film-based lightguide between the light input couplerand the base hold the ends of the lightguide positioning elements in theform of rods which may be moved along the rail while holding a region ofthe lightguide, thus changing the shape. In one embodiment, thelightguide or light emitting film positioning element is an extendedelement with a length more than twice as long as the width and theelement has one or more regions with a cross-sectional shape of a tube,rod, circle, annulus, ellipse, semicircle, rectangle, square, triangle,polygon, or closed curve with a curved region. In one embodiment, thefilm positioning element includes a light transmitting material and istranslucent or transparent.

In one embodiment, the lightguide positioning rod includes a slitthrough which the lightguide may be inserted and the rod may be rotatedand locked into place, such as by tightening a set screw in a guide slit(or opening) or a locking bolt in the guide rails. In one embodiment,the lightguide or light emitting film positioning rod includes a firstlinear rod component and a second linear rod component where the firstlinear rod component may be moved relative to the second linear rodcomponent such that the lightguide may be disposed between thecomponents to hold, increase tension, rotate, or otherwise guide thefilm location or orientation at the lightguide positioning rod. By usinga second and first linear component, the film is not required to be fedthrough a slot (in a positioning rod) and the rod may be added in themiddle of the light emitting device without requiring the removal of theother rods to feed the film through. In another embodiment, the use oftwo fixed light input couplers restricts or prohibits the film to be fedthrough a slit in the direction between the light input couplers, and atop and bottom component of the lightguide positioning rod is needed forfeeding the film through the rod without removing the end components(light input couplers in this example). For example, in one embodiment,the positioning rod includes a top component that may be removed fromthe bottom component and rejoined back to the rod after the film isplaced between the top component and the bottom component. In anotherembodiment, the top component is hinged to the bottom component.

Adjustable Tension Rails

In one embodiment, a light emitting device includes a film adjustmentmechanism in the form of one or more adjustable tension rails andlightguide or light emitting film positioning rods extending therefrom.In one embodiment, the lightguide or light emitting film positioning rodprovides an extended surface that is in contact with one or more regionsof the lightguide such that tension is applied to the film-basedlightguide or light emitting film to achieve a desired shape. Forexample, in one embodiment a light emitting device includes two primaryadjustable tension rails on opposite sides of a film-based lightguideincluding light input couplers disposed on two sides substantiallyorthogonal to the rails. In this embodiment, lightguide positioning rodsare physically coupled to secondary adjustable tension rails physicallycoupled to the primary adjustable tension rails and/or the secondaryadjustable tension rails extending from the primary adjustable tensionrails. By positioning the lightguide positioning rod at a distance awayfrom the primary adjustable tension rails by using the secondaryadjustable tension rails, the shape of the film-based lightguide may becontrolled using tension in the film-based lightguide between onelightguide positioning rod to another (or to a light input coupler). Inone embodiment, the location of the lightguide or light emitting filmpositioning rod along the primary or secondary adjustable tension railor the connection location of the primary adjustable tension rail withthe secondary adjustable tension rail may be adjusted using a screw,bolt, tightening screw, set screw, clamp, tightening and unlockingmechanism, groove and locking locations, guides and tabs, holes orgrooves and protrusions, fasteners, pins, straps, rings, clips, clamps,or other suitable temporary locking mechanisms or fasteners known in theart.

Flexible Adjustment Extension

In one embodiment, a light emitting device includes a film-basedlightguide or light emitting film and a film adjustment mechanism in theform of a flexible adjustment extension. In another embodiment, thelight emitting device includes at least one light input coupler, afilm-based lightguide extending from the light input coupler and atleast one flexible adjustment extension physically coupled to one ormore regions of the film-based lightguide such that it guides the shapeof the film-based lightguide in one or more directions. For example, inone embodiment, film adjustment mechanism is a pair of flexibleadjustment rods or tubes disposed alongside opposite sides of afilm-based lightguide (or light emitting film) with at least one lightinput coupler (or film support) disposed on a different side of thefilm-based lightguide (or light emitting film). In another embodiment,the flexible adjustment rods pass through holes in the film-basedlightguide or light emitting film. In this embodiment, the shape of theflexible adjustment rod can be changed by hand bending the rod into anew shape. The holes in the film-based lightguide or light emitting filmallow the region to move along the rod when it is bent and shape of thefilm can be altered. In another embodiment, the flexible adjustmentextension is solid or hollow with a cross-sectional outer shape of asquare, rectangle, triangle, other polygonal shape, or non-polygonalshape. In one embodiment, the shape of the film-based lightguide orlight emitting film substantially conforms to the shape of the flexibleadjustment extension. In another embodiment, the shape of the film-basedlightguide or light emitting film does not completely conform to theshape of the flexible adjustment extension. For example, in oneembodiment the film-based lightguide or light emitting film bows in adirection opposite that of a flexible adjustment rod in a region betweentwo adjacent holes. The flexible adjustment extension may besubstantially the same shape or a substantially different shape as thefilm-based lightguide in a light emitting device. For example, bybending one flexible adjustment rod downwards and the flexibleadjustment rod on the opposite side upwards, the film-based lightguideor light emitting film may be tilted at an angle in a particular region.In another embodiment, grommets are disposed in the holes in thefilm-based lightguide or light emitting film. Grommets can reduce thestress on a specific region of the hole or lightguide such that thelikelihood of tearing is reduced. In another embodiment, the film-basedlightguide or light emitting film is physically coupled to at least oneflexible adjustment extension by a loop in the film-based lightguide,light emitting film, glide mechanism, rolling mechanism, ring, or othertranslation device. For example, suitable translation devices includethose that are typically used with curtains or drapes such as curtainrings, guide rings, loops of material, runner, hook, and rollerrings/hooks. In one embodiment, the film-based lightguide or lightemitting film is bonded, clamped, or adhered to a ring and it may betranslated along a flexible adjustment tube. In another embodiment, theflexible adjustment extension includes a guide rail that supports arunner that is attached to the film based lightguide or light emittingfilm that can move along the flexible adjustment extension. In anotherembodiment, the translation device includes a locking mechanism thattemporarily or permanently prevents further movement of the translationdevice along the flexible adjustment extension. For example, in oneembodiment, the flexible adjustment rod is a hand bendable extrudedaluminum tube and spring clamps with substantially circular crosssections (for example, looped spring clamps such as those used onautomobile hoses) near one end are physically coupled to the lightguideor light emitting film. In this embodiment, by pressing on two levers ofthe spring clamp, the clamp opens to a wider diameter than the tube andthe clamp (and thus the region of the lightguide or light emitting filmit is physically coupled to) can be translated along the tube to adifferent location and the shape of the lightguide or light emittingfilm can be changed.

Light Emitting Strips or Extensions

In one embodiment, a light emitting device includes light emittinglightguide strips or extensions extending from a common light inputregion disposed to receive light from the input region and output thelight from one or more surfaces of the strips or extensions where thestrips or extensions have folded, bent or arcuate shaped regions. Forexample, in one embodiment, an array of lightguide strips cut from alight transmitting film are brought together in a bundle at one end anddisposed to receive light at their input edges from a light inputcoupler or light source such that light enters the strips and travels ina waveguide condition and exits the strips in light emitting regions dueto light extraction features. In one embodiment, the strips aresubstantially flexible and plastically deformable. In anotherembodiment, the light emitting device includes one or more of thefollowing: bendable side support rails, bendable mesh support,adjustable extension guides, lightguide or light emitting film (strip)positioning elements, adjustable tension rails, and flexible, adjustablelight emitting film extensions with a repeatedly adjustable shape. Forexample, in another embodiment, the strips have a white, lightreflecting film disposed between a flexible mesh and the striplightguides or extensions. In this embodiment, the shape and orientationof the strips can be adjusted by the user to direct light to desiredlocations or to a desired angular illumination output profile.

In another embodiment, the light emitting device includes a tubularshaped film-based lightguide including a light input coupler withcoupling lightguides extended from the film-based lightguide on one sideand output coupling lightguides on a second side. In this embodiment,the input coupling lightguides receive light from a light source andcouple the light into a film-based lightguide formed into a tube shapeand the light travels in the film-based lightguide where it is coupledinto output coupling lightguides and exits through light emittingregions. For example, in one embodiment, a light emitting deviceincludes a film-based lightguide with input coupling lightguides on oneside that are folded and bundled into a round tube shape and disposed tocouple light from a light source into a film-based lightguide. In thisembodiment, the film based lightguide includes a light mixing region ora non-emitting region that is curled into the shape of a tube and on theopposite side the output coupling lightguides extend from the film-basedlightguide and emit light in light emitting regions. In one embodiment,the output coupling lightguides may be shaped or formed to adjust theangular light output profile. In another embodiment, the output couplinglightguides include light emitting regions disposed at a distancegreater than one selected from the group of: 0.5, 1, 2, 4, 8, and 10feet from light source. In this embodiment, a film based lightguide, alight mixing region, a non-emitting region of the film-based lightguide,and/or an output coupling lightguide is longer than one selected fromthe group of: 0.5, 1, 2, 4, 8, and 10 feet in a direction substantiallyparallel to the optical axis of light propagating within the film-basedlightguide. In one embodiment, for example, a light source may belocated in a region with a plurality of arrangements of couplinglightguides extending therefrom and a plurality of light emittingregions extending from a plurality of film-based lightguides may bedistributed further away from the light source to provide a lightemitting system with distributed light emitting regions from acentralized light source.

Lightguide or Light Emitting Film Attachment Mechanism and Means forTranslation or Rotation

In one embodiment, the light emitting device includes a film adjustmentmechanism in the form of a lightguide or light emitting film attachmentmechanism and a means for translating or rotating the lightguide orlight emitting film attachment mechanism. The lightguide or lightemitting film attachment mechanism includes a component for physicallycoupling the mechanism to a region of the lightguide or light emittingfilm such that the lightguide or light emitting film is substantiallytranslated or rotated when the lightguide or light emitting filmattachment mechanism is translated or rotated. In one embodiment, thelightguide or light emitting film attachment mechanism includes one ormore of the following elements: a fastener, clamp, hook, loop, screw,bolt, tightening screw, set screw, clamp, tightening and unlockingmechanism, protrusion, pin, strap, ring, clip, clamp, and othertemporary or permanent locking mechanisms or a suitable fastener knownin the art. For example, in one embodiment, the lightguide or lightemitting film attachment mechanism is a plastic clamp pressed into alocking position such that it is affixed to a film-based lightguide orlight emitting film and the clamp further includes a hole through whicha rope is fed and tied in a knot. In this embodiment, opposite ends ofthe lightguide are physically coupled to a light input coupler and therope is also fed through a loop or eye-bolt physically coupled to thelight input coupler (or housing) such that when the rope is pulled, theclamp and the middle region of the lightguide to which it is clamped istranslated. In this embodiment, for example, the shape of the lightguidemay convert from that of one having a cross-section similar to that of abulb to one of a “flattened” bulb or a more planar-like shape. More thanone lightguide or light emitting film attachment mechanism may be usedon one or more sides or interior regions of a film-based lightguide orlight emitting film. For example, in one embodiment a flexiblelightguide drapes from the light input coupler above in a bulbous shape.A rope driven by a remote controlled motor in the housing of the lightemitting device pulls the lightguide attachment mechanism disposed inthe lower central region of the bulb toward the light input coupler suchthat the cross section has two inflection points on either side of thecentral region (such as in a cross-section similar to a “W” or rounded“W” shape).

Electronically Adjustable Shape

In one embodiment, the shape of the film-based lightguide or lightemitting film is changed by a motor translating or rotating a filmadjustment mechanism. In one embodiment, the motor is driven by wireless(such as infrared or IEEE 802.11g, for example) or wired controlmechanisms (such as a TCP/IP network connection). For example, in oneembodiment, a light emitting device includes an electrical motorcontrolled remotely using wireless transmission protocol that translatesa pair of lightguide or light emitting film positioning rods such thatthe shape of the lightguide or light emitting film and the angular lightoutput is changed.

Reconfigurable Light Output Profile

In one embodiment, the orientation or location of one or more lightemitting regions of the lightguide or light emitting film may bereconfigured (re-oriented, re-positioned, or both) by a film adjustmentmechanism such that the angular light output profile and/or the locationof one or more light emitting regions is changed. For example, in oneembodiment, a light emitting device includes at least one lightguide orlight emitting film that may be reoriented or repositioned to tilt orredirect the light in a first direction. In one embodiment, the lightemitting device includes a lightguide or light emitting film physicallycoupled to a plastically deformable material that allows the lightguideshape to be altered to achieve a specific light output profile such asmore light in the vertical direction, more light in the horizontaldirection, or more light away from the operator's eyes to reduce glare.

The light emitted from a particular light emitting region of a lightemitting device has an angle of peak luminous intensity. In someembodiments, the angle of peak luminous intensity varies across thelight emitting region. This variation can occur, for example, due tovariations in the shape of the light emitting region surface or aspatially varying light extraction region or light redirecting element.The angle of peak luminous intensity for a particular light emittingregion is the weighted average angle of peak luminous intensity for thelight emitting region and can be measured by the far field peak luminousintensity of the light emitted from only that particular light emittingregion. The average angle of peak luminous intensity for a lightemitting device is the weighted average angle of peak luminous intensityfor all of the light emitting regions of the light emitting device andis measured by the far field peak luminous intensity for the lightemitting device. In one embodiment, the shape, orientation, and/orlocation of one or more regions of the lightguide or light emitting filmincluding light emitting regions is adjusted and the angle of peakluminous intensity for the light emitting region is changed and theangle of peak luminous intensity for the light emitting device ischanged. In one embodiment, the light emitting device includes asubstantially non-light emitting region defined in an optical path oflight from the light source between the light source and the lightemitting region. In one embodiment, a curvature of the film-basedlightguide in the light emitting region is different from a curvature ofthe film-based lightguide in the substantially non-light emittingregion.

Elongated Light Emitting Device

In one embodiment, a light emitting device is longer in a firstdirection than a second and third direction with the first, second, andthird directions mutually orthogonal to each other. In one embodiment,the light emitting device includes a light input coupler with couplinglightguides extending substantially the length of the first, longdirection. In another embodiment, the light emitting device includes aplurality of light input couplers disposed along the first, longdirection to coupler light into a film-based lightguide along an inputedge. In one embodiment, the light emitting device includes an arcuatefilm-based lightguide. For example, in one embodiment an elongated lightemitting device includes a light source coupling light into a first andsecond set of coupling lightguides. In this embodiment, the first set ofcoupling lightguides directs light into a film-based lightguide in afirst direction and the second set of coupling lightguides direct lightinto the film-based lightguide in a second direction opposite to thefirst. In this embodiment, for example, coupling lightguides cut fromopposite sides of a lightguide film may be collected into two collectivesets that are curled under the lightguide such that the light inputsurface of both sets coupling lightguides are positioned to receivelight from a light source and the shape of the lightguide is arcuate orincludes a curved region. In one embodiment, coupling lightguides arefolded underneath the film-based lightguide, and the couplinglightguides are substantially disposed within the volume encapsulated orpartially encapsulated by the curved film-based lightguide with thelight emitting device requiring less volume than one with couplinglightguides external to a similar arcuate film-based lightguide. Forexample, in one embodiment the light emitting device is a replacementlight bulb for a linear fluorescent bulb and the coupling lightguides(and possible the light source) are be disposed inside the volumesubstantially encapsulated by the arcuate shaped film and the devicerequires less volume to achieve a uniform spatial luminance profile inthe light emitting region than other LED-based fluorescent bulbreplacements.

Vertical Draping Light Emitting Device

In one embodiment, the light emitting device includes a film-basedlightguide having a region that is suspended substantially verticallyand the film-based lightguide hangs downward due to gravity. Forexample, in one embodiment, the light emitting device is a suspendedlight fixture including a light input coupler, and a pair of lightguidepositioning rods. The lightguide film feeds through the lightguidepositioning rods and the end region of the film is suspended downward.In this embodiment, the film-based lightguide includes a light emittingregion at the end region and the light extraction features of thelightguide redirect the a majority of the light out of the lightguide ata substantially steep angle from the surface normal (such as within theangular range from 70 to 90 degrees from the surface normal) and thelight emitting device has a substantially directional light output inthe downward direction (such as a light output profile with at least 80%of the light output within 60 degrees of the nadir). In anotherembodiment, the lightguide positioning rods may be adjusted such thatthe vertical draping light emitting device is converted to a lightemitting device with a light emitting film-based lightguide oriented ina wave shape extending less in the vertical direction. In thisembodiment, the light output profile can be adjusted by changing theorientation and length of the draping region (and thus shape) of thefilm-based lightguide.

In one embodiment, a light emitting device includes a film-basedlightguide or light emitting film with a light emitting region orientedsubstantially vertically and the light exiting the lightguide has aluminous intensity in a light emitting region less than 300 candelas at55 degrees from the nadir (−x direction) in the x-y plane with thethickness of the lightguide in a light emitting region substantially inthe y direction. In one embodiment, the light is emitted from either orboth surfaces of the substantially vertical region of the film-basedlightguide in the light emitting region. For example, in one embodiment,more than 80% of the light emitted from the light emitting device iswithin one angular range selected from the group of: 50 degrees, 40degrees, 30 degrees, and 20 degrees from the nadir (−x direction).

Bulbous Light Emitting Device

In one embodiment, a light emitting device includes a film-basedlightguide or light emitting film with a region that is formed into abulbous shape. In another embodiment, the coupling lightguides couplelight into the periphery region of the bulbous shaped lightguide regionof the film-based lightguide. For example, in one embodiment, a regionof a planar film-based lightguide is vacuum thermoformed into the shapeof a bulb and coupling lightguide strips are cut radially from thebulbous region and brought together to provide an arrangement of lightinput surfaces disposed to receive light from a light source. In thisembodiment, the light is effectively entering the light emitting regionof the bulbous shaped film-based lightguide through all of theperipheral directions due to the radially extending couplinglightguides. Other shapes and form factors of the film-based lightguideor light emitting film or sub-region thereof including one or more lightemitting regions may similarly be formed into the film by thermoforming,vacuum thermoforming, hot pressing, compression molding, cold forming,or other techniques known in the art to form a film into a shape.Similar circular or round shapes, such as discs, bowl-shapes, cylinders,and/or cones, for example, may also be formed with radially extendedcoupling lightguides.

Dome Shaped Light Emitting Device

In one embodiment, a light emitting device includes a film-basedlightguide or light emitting film formed substantially into the shape ofa dome or hemisphere. For example, in one embodiment, two sets ofcoupling lightguides from opposite sides of a film-based lightguideformed with a dome region between are folded and brought together toreceive light from a light source disposed substantially within the domeregion. In this embodiment, the light travels in opposite directions dueto the two sets of coupling lightguides from opposite ends of thefilm-based lightguide. In another embodiment, light travels with anoptical axis substantially in one direction from the light source in thefilm-based lightguide formed with a dome-shaped region. In anotherembodiment, the light travels in radial directions from a light sourcethrough a dome-shaped region of a film-based lightguide due to couplinglightguides formed by radial cuts from a dome region. In anotherembodiment, a light emitting device includes a film-based lightguidewith a dome-shaped region and one or more of the following: a lightsource, a thermal transfer element, a camera, and an electrical driverdisposed substantially within (or substantially encapsulated by) thedome-shaped region volume, outside the dome-shaped region volume, orpartially within and partially outside the dome-shaped region volume.

Light Emitting Device is a Replacement Light Bulb

In one embodiment, the light emitting device is a replacement light bulbor a light source that can be electrically coupled to a light fixture.As used herein, a “light bulb” is not necessarily bulbous or round inshape and may also represent light emitting devices with non-bulbous,flat regions, or shapes with curves and flat regions and other shapes asis commonly used for a “light bulb” such as linear fluorescent bulbs andhalogen bulbs, for example. In one embodiment, a light emitting deviceis a replacement light bulb that includes a film-based lightguide withan arcuate shape and a light source disposed to couple light throughcoupling lightguides into the film-based lightguide. In anotherembodiment, the light emitting device is a light bulb including asubstantially planar light emitting region on a film-based lightguide orlight emitting film. In one embodiment, the light emitting devicefurther includes a protective cover or bulb-shaped lens disposed toreceive and transmit light from light emitting regions of the film-basedlightguide or light emitting film to the exterior of the light emittingdevice. In one embodiment, the light emitting device receives electricalpower through one or more bases, such as an Edison type screw base,Edison E27 type screw base, E5, E10, E11, E12, E14, E17, E17, E26, E27,E39, E40, bayonet, bipin, festoon base, Fluorescent T8 base, FluorescentT5, Fluorescent T5HO, PAR 36, MR11, MR16, MR8, single contact bayonet,double contact bayonet, S8 wedge, G4 BiPin, G5.3 BiPin, wedge, T5 wedge,ormini-can. In one embodiment, the light emitting device is areplacement light bulb or light source with an electrical connectordisposed to receive electrical power and emit light wherein the lightemitting device further includes one or more of the followingcomponents: an electrical base connector, a thermal transfer element, anelectrical driver, an electrical component, an LED, a light source, alight input coupler, a circuit board, a sensor, a control component, anoptical feedback component, and a communication component, where thecomponent is disposed within the base, disposed within the volumesubstantially enclosed by the protective housing, disposed within thehousing of the light emitting device, or is part of the outer surface ofthe light emitting device. For example, in one embodiment, the lightemitting device includes a protective lens with light redirectingsurface features disposed on an inner surface of the lens disposed toredirect and transmit light through the lens and out of the lightemitting device.

Front Light Illumination Device

In one embodiment, the light emitting device includes a light emittingregion with light extraction features that is disposed to illuminate aregion of a reflective display and transmit light reflected from thereflective display back through the substantially transparent regions ofthe light emitting region between the light extraction features. Forexample, in one embodiment, the light emitting device includes afilm-based lightguide laminated to an inner surface of a glass windowpositioned in a picture frame with the coupling lightguides and lightsource disposed within the picture frame. In this embodiment, the lightfrom the light emitting regions is directed toward a picture in theframe and the light is reflected from the picture and transmittedthrough the film-based lightguide and glass window. In anotherembodiment, the light emitting device is a frontlight for a reflectivedisplay disposed adjacent the light emitting region of the film-basedlightguide. In one embodiment, the light emitting device includes afilm-based lightguide with a light emitting region including lightextraction features that emits a light flux away from the light emittingdevice greater than one selected from the group of: 2, 5, 10, 20, 30,50, and 100 lumens in a first direction with a directional componentparallel to a surface normal to one side of the frontlight. The lightemitting region has an average ASTM D1003 luminous transmittancemeasured according to ASTM D1003 with a BYK Gardner haze meter greaterthan one selected from the group of: 50%, 60%, 70%, 80%, 90%, and 95% ina second direction opposite the first direction. In another embodiment,the light emitting device includes a film-based lightguide with a lightemitting region including light extracting surface features that emits alight flux away from the light emitting device greater than one selectedfrom the group of: 2, 5, 10, 20, 30, 50, and 100 lumens in a firstdirection with a directional component parallel to a surface normal toone side of the frontlight. The light emitting region has an averageclarity measured with a BYK Gardner haze, transmittance, and claritymeter greater than one selected from the group of: 70%, 80%, 88%, 92%,94%, 96%, 98%, and 99% in a second direction opposite the firstdirection.

Frontlight and Light Fixture

In one embodiment, the light emitting device is a frontlight and a lightfixture emitting light at two significantly different average luminousintensities within two non-overlapping angular ranges. For example, inone embodiment, the light emitting device is a frontlight for a display(such as a wall-mounted self-luminous picture frame) and a light fixture(such as wall-mounted uplight) providing high angle illumination of theceiling that emits light such that the average luminance of the lightemitting surface normal to the light emitting surface is (in the “on”state or illuminating a diffuse white reflecting material with 70%reflectance) less than 500 Cd/m² and the average luminance of the lightemitting surface at an angle within a range between and including 60degrees and 90 degrees from the normal to the light emitting surface isgreater than 2,000 Cd/m². In another embodiment, the light emittingdevice is a frontlight for a display (such as a wall-mountedself-luminous picture frame) and a light fixture (such as wall-mounteduplight) providing high angle illumination of the ceiling that emitslight such that the luminous intensity of the light emitting devicenormal to the light emitting surface is (in the “on” state orilluminating a diffuse white reflecting material with 70% reflectance)less than one selected from the group of: 100 Candelas, 200 Candelas,300 Candelas, 400 Candelas, and 500 Candelas and the average luminanceof the light emitting surface at an angle within a range between andincluding 60 degrees and 90 degrees from the normal to the lightemitting surface is greater than one selected from the group of: 500,750, 1000, 2000, 3000, 4000, and 500 Candelas. In another embodiment,the light emitting device includes a light emitting surface functioningas a display with a first peak luminous intensity output within a firstangular range (in the “on” mode, white mode or illuminating a whitediffusely reflecting material with 70% diffuse reflectance) and thelight emitting surface functions as a light fixture within a secondangular range not overlapping the first angular range with a second peakluminous intensity wherein the ratio of the second luminous intensity tothe first luminous intensity is greater than one selected from the groupof: 2, 5, 7, 10, 15, 20, 30, 40, 60, and 80. In one embodiment, one ormore cladding regions include light extraction features on a surfaceopposite the film-based lightguide and light from a light source iscoupled into the cladding region(s) such that the light from thecladding region(s) provide illumination as a light fixture and the lightextracted from the core region provides backlight or frontlightillumination for a passive or active display. For example, in oneembodiment, a cladding region is position on each side of a film-basedlightguide is three times as thick as the core region. A plurality ofLEDs are disposed to couple light into a stack of coupling lightguidesextending from the film-based lightguide such that more light ispropagating within the cladding regions that reaches the lightextraction features disposed on an outer surface or within one or morecladding regions than is propagating within the core region of thelightguide and reaches the light extraction features disposed on,within, or adjacent to the core region of the lightguide.

In another embodiment, the light emitting device operates as a displaybacklight or frontlight and is oriented substantially horizontally suchthat it displays information when looked down (or up) onto the displayand the display illuminates a wall, steps or other surface disposed toreceive the light. In a further embodiment, the light emitting device isa backlight for a display and light fixture. In another embodiment, thelight emitting device is a backlight or frontlight for a display andemits light out of the edge of one or more regions of the lightguide,core layer, cladding layer, or two or more cladding regions.

Preferential Light Output on One Side of the Lightguide

In one embodiment, a light emitting device includes a film-basedlightguide with a light transmitting region within a light emittingregion wherein the light flux emitted from a first side of thelightguide is substantially greater than the light flux emitted from asecond side of the lightguide opposite the first side. In oneembodiment, the light flux emitted from one side of the lightguide isgreater than one selected from the group of: 50%, 60%, 70%, 80%, 90%,95% and 99% of the light emitted from the light emitting device. Byhaving light transmitting regions within the light emitting regions,such as between light extraction features for example, and controllingmost of the light output to be emitted from one side, embodiments of thelight emitting device can function as a one-way light source, analogousto a one-way mirror. For example, in one embodiment, the light emittingdevice emits light from light extraction features that are sufficientlybright and small that the appearance from a predetermined distanceappears substantially uniform. This is analogous to a LED-basedbillboard sign wherein at a predetermined distance, the spacing regionsbetween the LEDs is not readily visible. In this embodiment, the regionsbetween the light extraction regions, for example, may be transparentsuch that a viewer can see through the light emitting region. In anotherembodiment, a camera is disposed on a side of the light emitting regionwith the lower light flux output such that the camera is not readilyvisible or ascertainable from the high light flux output side and thecamera can image regions of the environment on the opposite side of thelight emitting region. In one embodiment, the light emitting regionappears to be a substantially continuous light emitting surface from thehigh light flux emitting side of the light emitting region. In oneembodiment, the average pitch separation between the light extractionfeatures is less than one selected from the group of: 10, 5, 3, 2 and 1millimeters and the average luminance of the light emitting region isgreater than one selected from the group of: 50, 100, 200, 300, 500,1000, 2000, and 3000, 5000, and 10,000 cd/m². In another embodiment, thelight emitting device includes a film-based lightguide including a lightemitting region with light extraction features wherein a first lightemitting surface of the light emitting device emits more light receivedfrom a lightguide than a second surface of the light emitting device onthe opposite side of the lightguide than the first surface and lightabsorbing regions are disposed substantially between the lightextraction features and the second surface. For example, in oneembodiment a light emitting device includes a film-based lightguide withwhite printed dots with an average pitch of 1 mm on one side of a lightemitting region and black printed dots overprinted on top of the whiteprinted dots. In this embodiment, the light from within the lightguidescatters from the white printed dots and exits the lightguide and lightemitting device from the light emitting region on the opposite surfaceof the film-based lightguide than which the dots are printed. The blackdots substantially absorb light that is transmitted through the whitedot regions such that less light is emitted from the light emittingdevice on the side of the lightguide on which the dots are printed. Inone embodiment, the light absorbing regions are larger than the lightextraction features in at least one direction by one selected from thegroup of: 5%, 10%, 20%, 40%, 50%, 60%, 80%, 100%, and 150%.

Distributed Illumination System

In one embodiment, a distributed illumination system includes a lightemitting device including at least one light output coupler opticallycoupled to a distribution lightguide in a light transmitting region ofthe distribution lightguide. In one embodiment, the light output couplerincludes one or more of the following: a film-based lightguide, anoptical element, a light transferring element, a distributionlightguide, and a coupling lightguide. For example, in one embodiment, adistributed illumination system includes a light source disposed tocouple light into an array of coupling lightguides that are extensionsof a long thin strip film-based distribution lightguide. In thisembodiment, the light travels along the length of the distributionlightguide and is coupled out of the lightguide in light transmittingregions where the distribution lightguide is optically coupled to lightreceiving regions of a light output coupler lightguide film. In thisembodiment, the light travels through the light output couplerlightguide film and is extracted by light extraction features in a lightemitting region of the light output coupler lightguide film.

Light Output Coupler

More than one light output coupler may be used to couple light out ofthe lightguide at various locations along the lightguide. In oneembodiment, a first portion of the light incident on the light outputcoupler is specularly reflected or transmitted such that the light doesnot exit the light output coupler at the next interface due to arrivingat the interface at an angle less than the critical angle. By specularlyreflecting or transmitting a first portion of light, that light maycontinue to travel within the light output coupler without beingextracted within or near the light receiving region. For example, in oneembodiment, the light output coupler is a film-based lightguide disposedto receive a first portion of light from transmitting through the lighttransmitting region of the distribution lightguide in a light receivingregion. The light output coupler transmits the light to a light emittingregion including light extraction features further along the lightoutput coupler from the light receiving region. In one embodiment, alight output coupler directs light away from the light transmittingregion of the distribution lightguide and the light emitting region ofthe light output coupler is larger than the light receiving region.Thus, in this embodiment, the light output coupler is able to extract aportion of light from the lightguide and emit the light in a lightemitting area larger than the area that the light output coupler is inoptical contact with the lightguide. In one embodiment, thecross-sectional luminous flux density (measured perpendicular to theoptical axis of the light propagating within the lightguide inLumens/mm²) within the region of the distribution lightguide determinedby a thickness of the distribution lightguide and a width of the lighttransmitting region (in a direction orthogonal to the optical axis) atthe start of the light transmitting region is greater than the luminousflux density of the cross-section of the output coupling lightguide inthe region determined by a width of the light emitting region or theoutput coupling lightguide and a thickness of the output couplinglightguide at a beginning of the light emitting region. In anotherembodiment, the cross-sectional luminous flux density within a region ofthe output coupling lightguide (measured perpendicular to the opticalaxis of the light propagating within the lightguide in Lumens/mm²)determined by a width and a thickness of the light receiving region at abeginning of the light receiving region is greater than the luminousflux density of the cross-section of the region of the output couplingfilm determined by a width and a thickness of the light emitting regionat a beginning of the light emitting region. In another embodiment, aratio of the distribution lightguide luminous flux density at thebeginning of the light transmitting region to the luminous flux densityof the output coupling lightguide at the beginning of the light emittingregion is greater than one selected from the group of: 1, 2, 5, 10, 20,40, and 100.

In another embodiment, an average width of the light receiving region ofthe light output coupler in the direction substantially orthogonal tothe optical axis of the light within the film-based lightguide is lessthan an average width of the film-based lightguide (or distributionlightguide) at the region. In this embodiment, the amount of lightcoupled out of the distribution lightguide can be reduced by reducingthe width of the light receiving region of the light output coupler. Inanother embodiment, a light emitting device includes two or more lightoutput couplers optically coupled to a distribution lightguide whereinthe light transmitting regions of the distribution lightguide do notboth intersect a single line parallel to the optical axis of the lightwithin the film-based lightguide. In this embodiment, the lighttransmitting regions are not sequentially overlapping such that theyeach receive a portion of the light travelling within the lightguidethat is spatially separated from the other along a directionperpendicular to the optical axis of the lightguide. For example, in oneembodiment, one light output coupler transmits about 60% of the incidentflux into the light output coupler, and only about 40% of the lightremaining from that region of the distribution lightguide travels ontothe second output coupling lightguide. Separating the light outputcouplers laterally provides another variable of control for determiningthe flux of light output from the lightguide from a particular lightoutput coupler. In another embodiment, a light emitting device includestwo or more light output couplers optically coupled to a distributionlightguide with corresponding light transmitting regions that do notboth intersect a single line perpendicular to the optical axis of thelight within the film-based lightguide. In this embodiment, the lighttransmitting regions are not disposed substantially adjacent to eachother along the lightguide in a direction substantially orthogonal tothe optical axis. In this embodiment, one light output coupler isdisposed further along the distribution lightguide than the other suchthat a location of light output may be distributed further along in thedirection of the optical axis. In another embodiment, the lighttransmitting regions of the distribution lightguide corresponding tofirst and second light output couplers intersect a single lineperpendicular or parallel to the optical axis of the distributionlightguide. For example, a second light output coupler may be disposedpartially behind (further along the distribution lightguide) a firstlight output coupler. In another example, a second light output couplermay be disposed partially adjacent and behind a first light outputcoupler. In a further embodiment, the location of the light outputcouplers in a direction parallel or perpendicular to the optical axis ofthe light within the distribution lightguide is determined at least inpart by a desired output location of the light exiting a light emittingregion of the light output couplers. In another embodiment, the lightoutput coupler has an average thickness larger than the film-basedlightguide in the region of the light receiving region of the lightoutput coupler. In another embodiment, the light output coupler has anaverage width smaller than the film-based lightguide in the region ofthe light receiving region of the light output coupler.

In one embodiment, a location and an orientation of the light outputcouplers may be changed or first applied by the user or installer. Forexample, in one embodiment, the light output couplers may be applied tothe distribution lightguide upon installation. In another example, thelocation of the light output couplers may be changed by peeling back thelight output couplers and reapplying the light output couplers tooptically couple the light output couplers to the distributionlightguide by using low tack adhesives or low tack materials for all orpart of the film-based lightguide or light output coupler.

In another embodiment, a light emitting device includes a film-baseddistribution lightguide and an output coupling lightguide opticallycoupled to the distribution lightguide in a plurality of lighttransmitting regions. For example, in one embodiment, the outputcoupling lightguide is optically coupled to the distribution lightguideby strip coupling lightguides separated by fold regions. By dividing upthe light transmitting region into a plurality of smaller lighttransmitting regions that are separated from each other, a relativeuniformity of the flux within the lightguide may remain substantiallyuniform in a direction perpendicular to the optical axis. For example,in one embodiment, a light output coupler couples out 60% of the lightflux from the distribution lightguide and the cross-sectional luminousflux density uniformity in the lightguide in the region just past thelight output coupler is reduced. By separating out the lighttransmitting region and spreading the light transmitting region outspatially along a surface of the distribution lightguide, a uniformityof the light remaining in the lightguide is improved over a singlelarge, continuous light transmitting region.

In one embodiment, fold regions in the output coupling lightguideincrease a flexural rigidity or modulus of the output couplinglightguide in a plane perpendicular to the fold regions. In anotherembodiment, the fold regions allow for an increased light emittingsurface of the light output coupler. For example, in one embodiment, thelight output coupler includes a folded light emitting region andcoupling lightguides coupled to the distribution lightguide in lighttransmitting regions. A width of the light output coupler is larger thana width of the distribution lightguide in the direction orthogonal to athickness direction of the distribution lightguide and orthogonal theoptical axis of the light in the distribution lightguide.

Recycling Light Output Coupler

In one embodiment, a light emitting device includes a film-basedlightguide, a light input coupler, and a light output coupler includingoutput coupling lightguides disposed to receive light from within thefilm-based lightguide and direct the light through the output couplinglightguides to a specularly reflecting element such that the lightreturns through the coupling lightguides into the film-based lightguideand is recycled. In this embodiment, the light that passes through thelightguide without being extracted can be recycled by reflecting thelight through the use of output coupling lightguides and a specularreflector. In one embodiment, the specular reflector used for recyclingincludes one or more of the following: a retroreflective film (such asspecularly reflecting corner cube film), an aluminized component (suchas an aluminized PET film), a specularly reflecting aluminum component,and a specularly reflecting multilayer polymer film. In anotherembodiment, the film based lightguide includes more than one lightoutput coupler. For example, in one embodiment, a film-based lightguideincludes a light input coupler on a first edge of the lightguide andthree light output couplers optically coupled to three specularlyreflecting mirror films along the three remaining edges to efficientlyreflect back the light that is not extracted from the lightguide in thefirst pass.

Recycling Using Output Coupling Lightguides

In another embodiment, the light emitting device includes an inputcoupler disposed to couple light into a film-based lightguide and alight output coupler disposed to receive light from the film-basedlightguide. In this embodiment, the output coupling lightguides arefolded to redirect light into a region of the light input surface of aplurality of input coupling lightguides in the input coupler. In anotherembodiment, a portion of the light propagating through the lightemitting region of the light emitting device that is not emitted isrecycled by propagating through output coupling lightguides with endsdisposed to emit light into a region of the light input coupler. In thisembodiment, a portion of the light within the lightguide is recycledback into the lightguide. For example, in one embodiment a lightemitting device includes a light input coupler including couplinglightguides disposed along a first side of a film-based lightguide and alight output coupler including output coupling lightguides disposed on asecond side opposite the first side. In this embodiment, the outputcoupling lightguides in the light output coupler are folded three timessuch that light travels alongside the film-based lightguide edgedisposed between the first and second sides and the light emitting endsof the coupling lightguide are optically coupled to input light into aregion of the input coupling lightguides. In this embodiment, two ormore of the output coupling lightguides may be physically separatedalong the second side of the film-based lightguide and the region alongthe second side between the output coupling lightguides may includereflective features along the side such as 90 degree triangular cuts inthe film that reflect light back into the light emitting region of thefilm-based lightguide.

Removable Cladding Region

In one embodiment, the distributed illumination system includes acladding region optically coupled to the lightguide that may beremovable or repositionable. In another embodiment, the cladding may beseparated from the lightguide in a light transmitting region and a lightoutput coupler may be disposed in optical contact within the lighttransmitting region. For example, in one embodiment, a distributedillumination system includes a light source disposed to couple lightinto an array of coupling lightguides that are extensions of a long thinstrip film-based lightguide. In this embodiment, the light travels alonga length of the distribution lightguide film and substantially remainsin the lightguide in a region beneath the cladding region. The claddingregion is removed, exposing a light transmitting region of the coreregion. A light output coupler is optically coupled to the lightguide atthe light transmitting region such that a portion of light within thelightguide is coupled out of the lightguide into the light transmittingregion. In this embodiment, light travels through the light outputcoupler lightguide film and is extracted by light extraction features ina light emitting region of the light output coupler lightguide film. Inanother embodiment, the cladding region is a flap including a tab thatallows it to be easily pulled away from the lightguide while remainingphysically coupled to the distributed illumination system such that alight output coupler may be optically coupled to the lightguide. Forexample, the light output coupler is optically coupled to the lightguideby pressing a tacky film-based light output coupler onto the core regionof the lightguide film. In a further embodiment, the flap is laid backonto the light output coupler after the flap is optically coupled to thelight transmitting region on the distribution lightguide. When there isa desire to replace or change the light output coupler, the light outputcoupler may be removed and the old or a new cladding region may bere-applied, adhered or otherwise optically coupled to the lightguide.

In another embodiment, the lightguide is a tacky film, such as asilicone film, and the cladding layer is peeled away from the lightguidesuch that the cladding layer is not physically coupled to thedistributed illumination system. The tacky film, in this embodiment,helps hold on the cladding region and promotes adhesion of the lightoutput coupler to the lightguide or a new or the same cladding regionsubsequent to removal of the light output coupler.

Luminous Patterns, Signs, and Window Displays

In another embodiment, a light emitting device is used as an overlaywith indicia that can be illuminated. In one embodiment, the lightguideregion has a low degree of visibility in the off-state, and in theon-state can be clearly seen as illuminated indicia or luminouspatterns. In another embodiment, the light emitting device is aubiquitous display that displays information in the environment of theviewer. For example, in one embodiment, the light emitting device isdisposed in a frame adjacent a photograph with a matte board. The lightemitting device is a frontlight with a first light emitting region on afirst lightguide including a light emitting region adjacent thephotograph emitting white light to illuminate the photograph. The devicefurther includes a second light emitting region on a second lightguideadjacent the white matte board around the photograph that illuminatesthe matte board with green light based on positive health information(or red information based on negative health information) of theindividual in the photograph received by the light emitting deviceacross a wireless network connected to a wireless personal healthmonitor on the individual.

In another embodiment, a light emitting device is used as an overlaywith indicia that can be illuminated. In one embodiment, the lightguideregion has a low degree of visibility in the off-state, and an in theon-state can be clearly seen as illuminated indicia. For example, thelightguide region may be printed with light scattering dots toilluminate and display indicia such as “Warning,” “Exit,” “Sale,” “EnemyAircraft Detected,” “Open,” “Closed,” “Merry Christmas,” etc. Thelightguide region may be disposed on the viewing side of a display (suchas a liquid crystal display, plasma display, projection display, etc.)or it may be placed on a store or home window, on a table surface, aroad sign, on a vehicle or air/water/land craft exterior or window, overor inside a transparent, translucent, or opaque object, on a door,stairs, in a hallway, or within a doormat, etc. The indicia may also beicons, logos, images, or other representations such as a cartoon-likedrawing of Santa Claus, a brand logo such as the Nike “Swoosh”, a photoof a beach scene, a dithered photo of the face of a person, etc. Theindicia may be full-color, monochrome or comprise mixtures of colored ormonochrome regions and may be layered or employ phosphors, dyes, inks orpigments to achieve colors. In another embodiment, the light emittingdevice is a ubiquitous display that displays information in theenvironment of the viewer. For example, in one embodiment, the lightemitting device is disposed in a frame adjacent a photograph with amatte board where the light emitting device is a frontlight with a firstlight emitting region on a first lightguide comprises a light emittingregion adjacent the photograph emitting white light to illuminate thephotograph and the device further comprises a second light emittingregion on a second lightguide adjacent the white matte board around thephotograph that illuminates the matte board with green light based onpositive health information (or red information based on negative healthinformation) of the individual in the photograph received by the lightemitting device across a wireless network connected to a wirelesspersonal health monitor on the individual.

By using a lightguide film which is substantially not visible in theoff-state, the display, sign, or light emitting device can be employedin more places without substantially interfering with appearance of theobject on which it is disposed. In another embodiment, the lightemitting device provides illumination of a space wherein the regionwhich emits light in the on-state is not readily discernable in theoff-state. This, for example, can provide thin light fixtures orillumination devices that are substantially only visible in theon-state. For example, vehicle tail lights, seasonal window filmdisplays, ceiling mounted light fixtures, lamps, closed signs, roadhazard signs, danger/warning signs, etc. may be substantially invisiblein the off-state. In some situations, this enables the signs to beposted and only turned on when needed and can reduce delays incurred dueto the installation time required. In another embodiment, the lightemitting device is a light fixture which appears to be the color of thebackground surface upon which it is place upon in the off-state. Inanother embodiment, the light emitting area of the light fixture issubstantially black or light absorbing in the off-state. Such displaysare useful in submarines or other aircraft under NVIS illuminationconditions.

In a further embodiment, the lightguide film comprises a cladding regiondisposed between the core layer and a light absorbing layer. Forexample, the light redirected by the light extraction features intoangles less than the critical angle between the core layer and thecladding layer may be at an angle that remains within a lightguidecondition of a window-air interface when the lightguide is opticallycoupled to a window. In this example, the light will remain trappedwithin the window and lightguide film until it is absorbed orre-directed out of the lightguide. Scratches, fingerprints, and otherblemishes on the window may be illuminated by this light and the lightredirected out of the window causing visible artifacts. In oneembodiment, a light absorbing coating, layer or region is disposedbetween a cladding layer and the window and substantially absorbs thelight through the multiple TIR reflections and reduces the visibility ofthis artifact. In another embodiment, the light absorbing region,coating, or layer has an average specular light transmission (includingspecular reflections) for the wavelength range of at least one lightsource for the light emitting device less than one selected from thegroup of 85%, 80%, 75%, 70%, and 65%. In one embodiment, placing thelight absorbing region on the opposite side of the cladding region thanthe core region (and by not placing the light absorbing material insidethe cladding region), only the light passing through the cladding layerwill reach the light absorbing region. In the previous embodiment, whenthe lightguide is optically coupled to a window, the light that willexit the window only passes through the light absorbing layer once whilethe light trapped within the glass will pass through many times and willhave a greater chance of being significantly reduced in intensity beforereaching a light extracting artifact (scratch, fingerprint, etc.) on thewindow. In another embodiment, the lightguide has an average specularlight transmission (including specular reflections) for the wavelengthrange of at least one light source for the light emitting device lessthan one selected from the group of 85%, 80%, 75%, 70%, and 65%.

Lightguide Adjacent to a Window

In one embodiment, the lightguide film is substantially separated fromthe window by an air gap. In another embodiment, the light extractionfeatures in the lightguide film do not redirect light into an anglewithin the window greater than the critical angle of the window(typically angles greater than about 42 degrees from the surfacenormal). In one embodiment, the lightguide film is held in place bystandoffs or physically coupling the lightguide, light input coupler,housing or other element of the light emitting device to the window,frame, or other element disposed in proximity to the window. In anotherembodiment, the lightguide is disposed proximate the window and issupported by a stand, a hanging mechanism to a wall or ceiling, or amount to a wall or ceiling, for example.

In one embodiment, a light emitting device includes a light source,coupling lightguides, a lightguide including a light emitting region,and a mechanism or component for physically coupling the lightguide to awindow or window frame. For example, the lightguide may include anadhesive material (such as a “static cling” PVC film or silicone rubberfilm) disposed on one side of a core region of a lightguide such thatthe light emitting device may be laminated (by hand or with theassistance of a roller and/or application fluids, for example) to awindow such that the light emitting device supports its own weight. Inthis embodiment, the region of the lightguide not emitting light may besubstantially transparent and the light emitting region may besubstantially transparent, translucent, or partially transparent whenthe light source is turned off. In one embodiment, the light inputcoupler is disposed at the lower end of a lightguide such that the forcedoes not substantially pull the lightguide away from the window. Inanother embodiment, the adhesion layer is a cladding layer with arefractive index lower than a refractive index of the core layer. Thelightguide further includes a cladding layer on the opposite side of thecore layer. In another embodiment, the light emitting device is disposedon a window sill or other supporting structure with the lightguidephysically coupled to or disposed near the window. In anotherembodiment, the light emitting device includes one or more suction cupsthat physically couple the device to a substantially non-porous surface.For example, in one embodiment, a light input coupler disposed on thelower edge of a lightguide includes suction cups that adhere the lightinput coupler to a window. The lightguide film has a low peel-strengthadhesive, material, or region disposed to physically couple thelightguide film to a non-porous surface such as a window. In anotherembodiment, the lightguide film defines apertures through which portionsof a suction cup or a hook or extension thereof may pass through suchthat the lightguide film is supported vertically. Other suitablemechanical components such as latches, fasteners, hook and/or loopfasteners (using adhesive to bond the hook to the glass and the loop tothe light input coupler, for example) may be used to fasten or couplethe light emitting device or a component thereof (such as thelightguide) to a window or a substantially non-porous surface.

In another embodiment, a kit includes a light emitting device with anadhesive film or water soluble adhesive that will physically andoptically couple the lightguide to a glass window. In a furtherembodiment, the kit includes a roller suitable for moving an applicationliquid between the lightguide and a window, thus removing air bubblesand spreading the adhesive.

Signs and Window Displays

In another embodiment, a light emitting device is used as an overlaywith indicia that can be illuminated. In one embodiment, the lightguideregion has a low degree of visibility in the off-state, and an in theon-state can be clearly seen as illuminated indicia. For example, thelightguide region may be printed with light scattering dots toilluminate and display indicia such as “Warning,” “Exit,” “Sale,” “EnemyAircraft Detected,” “Open,” “Closed,” “Merry Christmas,” etc. Thelightguide region may be disposed on the viewing side of a display (suchas a liquid crystal display, plasma display, projection display, etc.)or it may be placed on a store or home window, on a table surface, aroad sign, on a vehicle or air/water/land craft exterior or window, overor inside a transparent, translucent, or opaque object, on a door,stairs, in a hallway, or within a doormat, etc. The indicia may also beicons, logos, images, or other representations such as a cartoon-likedrawing of Santa Claus, a brand logo such as the Nike “Swoosh”, a photoof a beach scene, a dithered photo of the face of a person, etc. Theindicia may be full-color, monochrome or comprise mixtures of colored ormonochrome regions and may be layered or employ phosphors, dyes, inks orpigments to achieve colors. In another embodiment, the light emittingdevice is a ubiquitous display that displays information in theenvironment of the viewer. For example, in one embodiment, the lightemitting device is disposed in a frame adjacent a photograph with amatte board where the light emitting device is a frontlight with a firstlight emitting region on a first lightguide comprises a light emittingregion adjacent the photograph emitting white light to illuminate thephotograph and the device further comprises a second light emittingregion on a second lightguide adjacent the white matte board around thephotograph that illuminates the matte board with green light based onpositive health information (or red information based on negative healthinformation) of the individual in the photograph received by the lightemitting device across a wireless network connected to a wirelesspersonal health monitor on the individual.

By using a lightguide film which is substantially not visible in theoff-state, the display, sign, or light emitting device can be employedin more places without substantially interfering with appearance of theobject on which it is disposed. In another embodiment, the lightemitting device provides illumination of a space wherein the regionwhich emits light in the on-state is not readily discernable in theoff-state. This, for example, can provide thin light fixtures orillumination devices that are substantially only visible in theon-state. For example, vehicle tail lights, seasonal window filmdisplays, ceiling mounted light fixtures, lamps, closed signs, roadhazard signs, danger/warning signs, etc. may be substantially invisiblein the off-state. In some situations, this enables the signs to beposted and only turned on when needed and can reduce delays incurred dueto the installation time required. In another embodiment, the lightemitting device is a light fixture which appears to be the color of thebackground surface upon which it is place upon in the off-state. Inanother embodiment, the light emitting area of the light fixture issubstantially black or light absorbing in the off-state. Such displaysare useful in submarines or other aircraft under NVIS illuminationconditions.

In a further embodiment, the lightguide film comprises a cladding regiondisposed between the core layer and a light absorbing layer. Forexample, the light redirected by the light extraction features intoangles less than the critical angle between the core layer and thecladding layer may be at an angle that remains within a lightguidecondition of a window-air interface when the lightguide is opticallycoupled to a window. In this example, the light will remain trappedwithin the window and lightguide film until it is absorbed orre-directed out of the lightguide. Scratches, fingerprints, and otherblemishes on the window may be illuminated by this light and the lightredirected out of the window causing visible artifacts. In oneembodiment, a light absorbing coating, layer or region is disposedbetween a cladding layer and the window and substantially absorbs thelight through the multiple TIR reflections and reduces the visibility ofthis artifact. In another embodiment, the light absorbing region,coating, or layer has an average specular light transmission (includingspecular reflections) for the wavelength range of at least one lightsource for the light emitting device less than one selected from thegroup of 85%, 80%, 75%, 70%, and 65%. In one embodiment, placing thelight absorbing region on the opposite side of the cladding region thanthe core region (and by not placing the light absorbing material insidethe cladding region), only the light passing through the cladding layerwill reach the light absorbing region. In the previous embodiment, whenthe lightguide is optically coupled to a window, the light that willexit the window only passes through the light absorbing layer once whilethe light trapped within the glass will pass through many times and willhave a greater chance of being significantly reduced in intensity beforereaching a light extracting artifact (scratch, fingerprint, etc.) on thewindow. In another embodiment, the lightguide has an average specularlight transmission (including specular reflections) for the wavelengthrange of at least one light source for the light emitting device lessthan one selected from the group of 85%, 80%, 75%, 70%, and 65%.

Optically Coupling Light into the Window

In one embodiment, a lightguide or light output coupling element isoptically coupled to a glass or plastic window such that light iscoupled into the window and travels within the window in a totalinternal reflection condition. By coupling light into a window, one canilluminate frosted or etched glass, films disposed on the window, orembossed plastic patterns such as logos or decoration on the window. Inone embodiment, the light coupled into the window is extracted by rain,water, or condensation on the window effectively forming lenses toprovide rain or weather indication or an aesthetic luminous effect. Inanother embodiment, light from a light source is coupled into a windowfrom a light output coupler or lightguide optically coupled to thewindow and a light extraction region or film is optically coupled to thewindow such that light escapes the window in the region of the lightextraction region. In the previous embodiment, the window is functioningas the core region of a lightguide. In one embodiment, the window haswavelength dependent absorption properties (such as absorbing red lightmore than blue light) and the output of the light from the lightguide orlight output coupler compensates for the absorption in order to achievea desired color such as white. For example, in one embodiment, the lightfrom the lightguide comprises more red light output than blue lightoutput to compensate for the green absorption in a soda-lime glasswindow.

Lightguide Adjacent to a Window

In one embodiment, the lightguide film is substantially separated fromthe window by an air gap. In another embodiment, the light extractionfeatures in the lightguide film do not redirect light into an anglewithin the window greater than the critical angle of the window(typically angles greater than about 42 degrees from the surfacenormal). In one embodiment, the lightguide film is held in place bystandoffs or physically coupling the lightguide, light input coupler,housing or other element of the light emitting device to the window,frame, or other element disposed in proximity to the window. In anotherembodiment, the lightguide is disposed proximate the window and issupported by one or more selected from the group of a stand, a hangingmechanism to a wall or ceiling, and a mount to a wall or ceiling.

In one embodiment, a light emitting device comprises a light source,coupling lightguides, a lightguide comprising a light emitting region,and a method for physically coupling the lightguide to a window orwindow frame. For example, the lightguide may comprise an adhesivematerial (such as a “static cling” PVC film or silicone rubber film)disposed on one side of a core region of a lightguide such that thelight emitting device may be laminated (by hand or with the assistanceof a roller and/or application fluids, for example) to a window suchthat the light emitting device supports its own weight. In thisembodiment, the region of the lightguide not emitting light may besubstantially transparent and the light emitting region may besubstantially transparent, translucent, or partially transparent whenthe light source is turned off. In one embodiment, the light inputcoupler is disposed at the lower end of a lightguide such that the forcedoes not substantially pull the lightguide away from the window. Inanother embodiment, the adhesion layer is a cladding layer with arefractive index lower than the core layer and the lightguide furthercomprises a cladding layer on the opposite side of the core layer. Inanother embodiment, the light emitting device may be disposed on awindow sill or other supporting structure with the lightguide physicallycoupled to or disposed near the window. In another embodiment, one ormore cladding layers of the lightguide comprises a protective coatingsuch as a hardcoating wherein the pencil hardness of the protectivecoating is greater than one selected from the group of 8H, 7H, 6H, 5H,4H, 3H, and 2H. In a further embodiment, the lightguide comprises anammonia resistant coating such that the coating does not show evidenceof crazing or whitening after 5 hours of exposure to 1% ammoniumhydroxide or 3% isopropyl alcohol. In a further embodiment, thelightguide comprises a tab region or other extended region thatphysically decouples the lightguide from a window when pulled.

In one embodiment, the lightguide is physically and optically coupled toa window (glass or plastic) and the transmittance through asubstantially non-light emitting region of the lightguide is greaterthan one selected from the group of 70%, 80%, 86%, 88%, 90% and 92%.Optically coupling the lightguide to the window can reduce orsubstantially eliminate the surface reflection from the innerlightguide-air and air window interfaces. This reduces the overallvisibility of the lightguide film and its light extraction features (theclose proximity required for optical coupling also reduces extraneousmultiple reflections).

In another embodiment, the light emitting device comprises one or moresuction cups that physically couple the device to a substantiallynon-porous surface. For example, in one embodiment, a light inputcoupler disposed on the lower edge of a lightguide comprises suctioncups that adhere the light input coupler to a window and the lightguidefilm has a low peel-strength adhesive, material, or region disposed tophysically couple the lightguide film to a non-porous surface such as awindow. In another embodiment, the lightguide film comprises holesthrough which portions of a suction cup or a hook or extension thereofmay pass through such that the lightguide film is supported vertically.Other mechanical means such as latches, fasteners, hook and loopfasteners (using adhesive to bond the hook to the glass and the loop tothe light input coupler, for example) may be used to fasten or couplethe light emitting device or a component thereof (such as thelightguide) to a window or a substantially non-porous surface.

In another embodiment, a kit comprises a light emitting device with anadhesive film or water soluble adhesive that will physically andoptically coupled the lightguide to a glass window. In a furtherembodiment, the kit comprises a roller suitable for moving anapplication liquid between the lightguide and a window, thus removingair bubbles and spreading the adhesive.

Light Emitting Packaging

In one embodiment, a light emitting device including a film-basedlightguide is disposed within or physically coupled to a packagingmaterial. In one embodiment, a packaging material or product includes alight emitting device including a light input coupler with a lightsource, and a light emitting region on a flexible film-based lightguide.In one embodiment, the film-based lightguide film is optically coupledto the packaging. In a further embodiment, the packaging includes atransparent region disposed to transmit light exiting the film-basedlightguide out of the package. In another embodiment, a light emittingdevice includes a film-based lightguide that substantially encloses oneor more objects such that the film-based lightguide is a packagingmaterial for the one or more objects. In this embodiment, the lightinput coupler may be disposed substantially within a volume of thepackaging, substantially outside the volume of the packaging, orpartially within and outside the volume of the packaging. In anotherembodiment, the light emitting regions of the packaging includesdesigns, outlines, logos, graphics, images, pictures, and indicia orcombinations thereof. In further embodiments, one or more of multiplefilm-based lightguide layers, different colored light sources, differentextraction regions, sensors, motion detectors, batteries, and otherdevices enable additional functionality, properties, appearance, and/orlight output profiles for the light emitting device incorporated into orwithin the packaging. In another embodiment, the packaging material,film-based lightguide, or both are shrink-wrap packaging materials. Inanother embodiment, the packaging material, film-based lightguide, orboth are heat-sealable packaging materials. In a further embodiment, aflexible photovoltaic panel is electrically coupled to the light inputcoupler to provide electrical power for the light emitting device. Inanother embodiment, the packaging includes a light emitting device witha battery power source. In another embodiment, the light emitted from alight emitting region flashes or “blinks” to attract attention andconserve battery life. In one embodiment, the packaging including thelight emitting device includes a motion detector that turns on the lightsource in the light input coupler when the package is moved, motion isdetected near the package, or when the package is moved and when motionis detected near the package.

Other Applications of the Light Emitting Device

Since embodiments enable inexpensive coupling into thin-films, there aremany general illumination and backlighting applications. The firstexample is general home and office lighting using roll-out films onwalls or ceiling. Beyond that, the film can bend to shape to non-planarshapes for general illumination. Additionally, it can be used as thebacklight or frontlight in the many thin displays that have been or arebeing developed. For example, LCD and E-ink thin-film displays may beimproved using a thin back-lighting film or thin front-lighting film;Handheld devices with flexible and scrollable displays are beingdeveloped and they need an efficient, low-cost method for getting lightinto the backlighting film. In one embodiment, the light emitting devicecomprises a light input coupler, lightguide, and light source whichprovide illumination for translucent objects or film such as stainedglass windows or signs or displays such as point-of-purchase displays.In one embodiment, the thin film enables the light extraction featuresto be printed such that they overall negligibly scatter light thatpropagates normal to the face of the film. In this embodiment, when thefilm is not illuminated, objects can be seen clearly through the filmwithout significant haze. When placed behind a transparent or partiallytransparent stained glass window, the overall assembly allowslow-scattering transmission of light through the assembly if desired.Furthermore, the flexibility of the film allows for much greaterpositional tolerances and design freedom than traditional platelightguide backlights because the film can be bent and adapted to thevarious stained glass window shapes, sizes and topologies. In thisembodiment, when not illuminated, the stained glass appears as a regularnon-illuminated stained glass window. When illuminated, the stainedglass window glows.

Additional embodiments include light emitting devices wherein thestained glass window is strictly aesthetic and does not require viewingof objects through it (e.g. cabinet stained glass windows or artdisplays), and the overall see-through clarity of the backlight does notneed to be achieved. In this embodiment, a diffuse or specular reflectorcan be placed behind the film to capture light that illuminates out ofthe film in the direction away from the stained glass window. Diffusingfilms, light redirecting films, reverse prism films, diffuser films(volumetric, surface relief or a combination thereof) may be disposedbetween the lightguide and the object to be illuminated. Other films maybe used such as other optical films known to be suitable to be usedwithin an LCD backlight.

The light emitting device of one embodiment can be used for backlightingor frontlighting purposes in passive displays, e.g., as a backlight orfrontlight for an illuminated advertising poster, as well as for active(changing) displays such as LCD displays. Suitable displays include, butare not limited to, mobile phone displays, mobile devices, aircraftdisplay, watercraft displays, televisions, monitors, laptops, watches(including one where the band comprises a flexible lightguide which iscapable of illumination or “lighting up” in a predetermined pattern byan LED within the watch or watch band), signs, advertising displays,window signs, transparent displays, automobile displays, electronicdevice displays, and other devices where LCD displays are known to beused.

Some applications generally require compact, low-cost white-lightillumination of consistent brightness and color across the illuminatedarea. It is cost-effective and energy-efficient to mix the light fromred, blue, and green LEDs for this purpose, but color mixing is oftenproblematic. In one embodiment, light from red, blue, and green lightsources can all be directed into each stack of legs/input areas, and bythe time the light reaches the sheet, it will be sufficiently mixed thatit appears as white light. The light sources can be geometricallysituated, and adjusted in intensity, to better provide uniformintensities and colors across the body. A similar arrangement can beattained by providing stacked sheets (more specifically stacked sheetbodies or lightguides) wherein the colors in the sheets combine toprovide white light. Since some displays are provided on flexiblesubstrates—for example, electronic ink thin-film displays on printedpages—the sheets provide a means for allowing backlighting whilemaintaining the flexibility of the display's media.

In some embodiments, the light emitting device is a novel LCDbacklighting solution, which includes mixing multiple colors of LEDsinto a single lightguide. In one embodiment, the length and geometry ofthe strips uniformly mixes light into the lightguide region of the filmlightguide without a significant area of light mixing region locatedaround the edge. The enhanced uniformity of the colors can be used for astatic display or a color-sequential LCD and BLU system. One method fora color-sequential system is based on pulsing between red, green, andblue backlight color while synced to the LCD screen pulsing. Moreover, alayered version of red-, green- and blue-lighted films that combine tomake white light is presented. A pixel-based display region can havemultiple pixels that are designated to be red, green or blue. Behind itare three separate film lightguides that each have a separate color oflight coupled to them. Each of the lightguides has light extractionfeatures that match up with the corresponding color of the pixel-baseddisplay. For example red light is coupled into coupling lightguide andthen into the lightguide or lightguide region and is extracted from thefeature into the red pixel. The film lightguides are considerablythinner than the width of the pixels so that geometrically a highpercentage of the light from a given color goes into its correspondingset of pixels. Ideally, no color filter needs to be used within thepixels, but in case there is cross-talk between pixels, they should beused.

It is also notable that embodiments have utility when operated “inreverse”—that is, the light-emitting face(s) of a sheet could be used asa light collector, with the sheet collecting light and transmitting itthrough the legs to a photosensitive element. As an example, sheets inaccordance with embodiments could collect incoming light and internallyreflect it to direct it to a photovoltaic device for solar energycollection purposes. Such an arrangement can also be useful forenvironmental monitoring sensing purposes, in that the sheet can detectand collect light across a broad area, and the detector(s) at the legswill then provide a measurement representative of the entire area. Asheet could perform light collection of this nature in addition to lightemission. For example, in lighting applications, a sheet might monitorambient light, and then might be activated to emit light once twilightor darkness is detected. Usefully, since it is known that LEDs can alsobe “run in reverse”—that is, they can provide output current/voltagewhen exposed to light—if LEDs are used as an illumination source when asheet is used for light emission, they can also be used as detectorswhen a sheet is used for light collection. In one embodiment, thelightguide captures a portion of incident light and directs it to adetector wherein the detector is designed to detect a specificwavelength (such as by including a bandpass filter, narrowband filter ora diode with a specific bandgap used in reverse). These light detectiondevices have the advantages of collecting a percentage of light over alarge area and detecting light of a specific wavelength is directedtoward the film while the film/sheet/lightguide/device remainssubstantially transparent. These can be useful in military operationswhere one is interested in detecting lasers or light sources (such asused in sighting devices, aiming devices, laser-based weapons, LIDAR orlaser based ranging devices, target designation, target ranging, lasercountermeasure detection, directed energy weapon detection, eye-targetedor dazzler laser detection) or infra-red illuminators (that might beused with night vision goggles).

In another embodiment, a light emitting device comprises a light source,light input coupler, and film-based lightguide wherein the lightemitting device is one selected from the group of building mounted sign,freestanding sign, interior sign, wall sign, fascia sign, awning sign,projecting sign, sign band, roof sign, parapet sign, window sign, canopysign, pylon sign, joint tenant sign, monument sign, pole sign, high-risepole sign, directional sign, electronic message center sign, video sign,electronic sign, billboard, electronic billboard, interior directionalsign, interior directory sign, interior regulatory sign, interior mallsign, and interior point-of-purchase sign.

In some embodiments, the film-based lightguides or light emitting filmsare highly useful for use in illuminated signs, graphics, and otherdisplays. For example, the film may be placed on walls or windowswithout significantly changing the wall or window appearance. However,when the sign is illuminated, the image etched into the film lightguidewould become visible. Embodiments could also be useful for couplinglight into the films that sit in front of some grocery store freezers asinsulation. Lighting applications where there is limited space, such asin the ice at hockey rinks may also require plastic film lighting. Sincea sheet can be installed on a wall or window without significantlychanging its appearance, with the light-emitting area(s) becomingvisible when the light source(s) are activated, the embodiment allowsdisplays to be located at areas where typical displays would beaesthetically unacceptable (e.g., on windows). The sheets may also beused in situations where space considerations are paramount, e.g., whenlighting is desired within the ice of skating rinks (as discussed inU.S. Pat. No. 7,237,396, which also describes other features andapplications that could be utilized with embodiments). The flexibilityof the sheets allows them to be used in lieu of the curtains sometimesused for 15 climate containment, e.g., in the film curtains that aresometimes used at the fronts of grocery store freezers to bettermaintain their internal temperatures. The flexibility of the sheets alsoallows their use in displays that move, e.g., in light emitting flagsthat may move in the breeze.

Communication with the Light Emitting Device

In one embodiment, the light emitting device includes a communicationdevice coupled in signal communication to receive and/or transmitcommunication signals from or to external devices or the environment. Inone embodiment, the light emitting device communicates with one or moreof the following devices: a local computer, a remote computer or server,a cellular phone, PDA, an electronic reader (eBook or eReader, forexample), a short wave wireless communication device, such as aBluetooth® device, a microphone, a laptop, a portable computer, aportable communication device, an electronic watch, an electronicwallet, a thermometer, a radio, a television, a digital video recorder,a telephone, a stereo, an entertainment system, a home networkcontroller, a router, a modem, a satellite transmitter/receiver, awireless transmitter/receiver, a security system, an air conditioningsystem, an energy monitoring device, an occupancy sensor, a motionsensor, a printer, a tablet computer, a vehicle, such as an automobile,a watercraft, an aircraft, or a land craft, an electronic transportationdevice, a train, a bus, a subway, a light fixture, a health monitoringdevice, an internet connected device, a GPS device, a light sensingdevice, a lighting controller, an HVAC controller, a home or officeautomation controller, a garage door controller, a remote controldevice, a camera, a keyboard, a mouse, a pointing device, a projector, amonitor, a display (LCD, OLED, LED, or Plasma display, for example), avideo game system, and a video game controller.

In one embodiment, the light emitting device receives information fromor transmits information to the environment through one or more of thefollowing: an electrical connection, a wireless connection, a radiofrequency connection, an infrared-connection, visual light detectors orimagers, thermal detectors or imagers, a microphone, a transducer, asensor, an actuator, an accelerometer, an air flow sensor, a photodiode,an electronic display, a temperature sensor, a humidity sensor, amagnetic field sensor, a metal detector, a chemical sensor, a molecularsensor, a biological material sensor, and a biosensor. In anotherembodiment, in response to information received directly or throughanalysis of information received by the light emitting device, one ormore of the following properties of the light emitting device including,without limitation, light flux output, color of the light output,infrared light flux output, ultraviolet light flux output, wavelength ofthe light output, angular light output profile, spatial light outputprofile, luminance, luminance uniformity, color uniformity, rate oflight output (frequency), polarization, image displayed, logo displayed,indicia displayed, angle of peak luminous intensity, angular full-widthat half maximum intensity in one or more light output planes, size ofthe light emitting region, location of the light emitting region,orientation of the light emitting region, shape of the light emittingregion, dimension of the light emitting region in a direction, dimensionof the light emitting device, perceived transmittance or “see-through”,sound output, output communication to another device, and rate of changeor duration of one or more of the aforementioned properties in one ormore regions or lightguides changes.

Radio Frequency Communication

In one embodiment, the light-emitting device has a radio frequencytransmitter and a receiver that receives and transmits information. In afurther embodiment, the light emitting device changes a property due toradio frequency communication with a device. In one embodiment, theradio frequency transmitter transmits and receives the frequency-hoppingspread spectrum radio technology. In another embodiment, thelight-emitting device includes a radio transmitter and receiver thatreceives and transmits radiation by Gaussian frequency-shift keying(GFSK). In another embodiment, the light-emitting device has a shortwavelength radio transmission protocol, such as Bluetooth® protocol,radio frequency transmitter and receiver that receives and transmitsinformation. In another embodiment, the light-emitting device includesan IEEE 802.11 compliant radio transmitter and receiver. In anotherembodiment, the light-emitting device includes an IEEE 802.15.4-2003,ZigBee® RF4CE, or ZigBee® compliant radio transmitter and receiver. Forexample, in one embodiment, the light emitting device receivesinformation from a wireless router using an IEEE 802.11 protocol thatdirects the light emitting device to change the relative light outputfrom two different colored LEDs and the light emitted from the lightemitting device changes color.

In another embodiment, the light-emitting device includes a radiotransceiver compliant to at least one communication standard forcreating a wide area network (WAN) selected from the group of: iBurst™,Fast Low-latency Access with Seamless Handoff-Orthogonal FrequencyDivision Multiplexing (Flash-OFDM™), Wi-Fi: 802.11 standard, WiMAX:802.16 standard, UMTS over W-CDMA, UMTS-TDD, EV-DO×1 Rev 0, Rev A, Rev Band ×3 standards, HSPA D and U standards, RTT, GPRS, and EDGE. Inanother embodiment, the light-emitting device includes a radiotransceiver compliant to at least one communication standard forcreating a local area network (WLAN) selected from the group of: IEEE802.11-2007, IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, andamended IEEE 802.11-2007 standards or protocols. In a furtherembodiment, the light-emitting device includes a radio transceivercompliant to at least one communication standard for creating a personalarea network (WPAN) selected from the group of: short wavelengthwireless transmission protocol, such as Bluetooth® protocol (includingstandard protocol and low energy protocol), high level communicationprotocol such as ZigBee® Wireless USB, UWB, IPv6 over Low power WirelessPersonal Area Networks, ONE-NET™, Z-Wave®, and EnOcean® standards. Inanother embodiment, the light emitting device includes a transceiverdisposed to receive and transmit radio frequency information over acellular phone connection protocol selected from the group of: CDMA,GSM, EDGE, 3G, UMTS, and SMS. In another embodiment, the light-emittingdevice includes 2 or more radio frequency transceivers configured toreceive similar or different protocols, such as Bluetooth® protocol and802.11 protocol, for example.

Infrared Communication

In one embodiment, the light-emitting device includes an infraredphotodetector, a phototransistor or an infrared (IR) receiver disposedto receive IR light. For example, in one embodiment, in one lightemitting device a light source in a first light input coupler for afirst film-based lightguide is turned off and a second light source in asecond light input coupler for a second film-based lightguide is turnedon in response to information received from or through an infraredreceiver from an infrared remote control to change a logo displayed onthe light emitting device from “OPEN”’ to “CLOSED,” for example.

Communication Architecture and Protocol

In one embodiment, the light emitting device communicates with a seconddevice used in a wired connection. In another embodiment, the connectionbetween the light emitting device and the second device includes one ormore of the following connections: serial, asynchronous serial,parallel, and USB. In one embodiment, the light emitting devicecommunicates with a second device using one or more communicationarchitectures, network protocols, data link layers, network layers,network layer management protocols, transport layers, session layers,and/or application layers.

Light Detector

In one embodiment, the light emitting device includes a photodetector ora light detector disposed to receive and process light into information.For example, in one embodiment, the light emitting device includes acamera disposed to capture an image, recognize an object, individual, orproperty of the individual or object, such as gender, height, age,and/or race, for example, and change a property of the light emittingdevice. In another embodiment, the light emitting device includes aphotodetector to detect the ambient light intensity and adjust theluminous intensity of the light output from the light emitting device tosave energy or make the display or light emitting region more visible.In another embodiment, the light emitting device includes a motionsensor, occupancy sensor, or smoke detector using a photodetector.

Light Emitting Device Comprises a Microphone

In one embodiment, the light emitting device includes one or moremicrophones and local or remote components for analyzing and recognizingspeech and changing the output of the display. For example, in oneembodiment, a system of light emitting devices disposed on an innersurfaces of a bank of refrigeration coolers includes microphonesdisposed to recognize speech from a customer or to determine a specificproduct stated and subsequently increase a illuminance or light outputin a flashing manner in a corresponding region of the cooler includingthe product such that the product can be easily found by the customer.In this embodiment, for example, a location of the product and thecorresponding lightguide regions may be programmed by the installer orsomeone refilling the coolers by talking to the device and engaging asetup or configuration mode by a button or a speech command and cyclingor directly changing a region for a particular product. In anotherembodiment, the installer or person refilling the cooler may change thelocation of the products (and thus the appropriate regions to beilluminated) by an application on a cellular phone or communicationdevice. In another embodiment, the light emitting device recognizesspeech through the microphone and changes one or more propertiesaccordingly. For example, in one embodiment, an individual speaks theseries of commands “Light Fixture Command,” “Brightness Two,” “Spot,”“Warm White.” In this embodiment, after processing the commands, thelight emitting light fixture will dim to a brightness level of two outof ten, change the color to a warm white, and adjust the shape of thelight emitting region to create a narrow angular light output, forexample.

User Identification and Preferences

In another embodiment, the light emitting device receives informationfrom a device that indicates or provides information for determining oneor more preferences or properties associated with the user of thedevice. For example, in one embodiment, a user with a cellular phonewith a Bluetooth® compatible radio transceiver is identified throughcommunication with the light emitting device through Bluetooth® protocolcommunication and the user's preferences are analyzed by the lightemitting device (or a remote server) such that the light emitting deviceprovides illumination for the lightguide in the lightguide stack for alogo of the user's favorite soft drink. In another embodiment, the lightemitting device receives biometric information such as face recognition,fingerprint recognition, and/or retinal scan, for example, and processesthe information or sends the information to a remote server thatprocesses the information such that a property of the light emittingdevice changes. In another embodiment, the light emitting devicedisplays targeted information to the individual that the light emittingdevice or a controller operatively coupled to the light emitting devicehas identified based on information related to the individual or thedevice. For example, if the light emitting device has identified aperson and the associated property that the person has a very highcredit limit or typically charges for large purchases (such as by an“electronic wallet” application on the person's smartphone) the lightemitting device illuminates the higher priced items with a higherilluminance or displays a particular logo designed for a target marketof wealthy individuals.

Angular Profile of Light Emitting from the Light Emitting Device

In one embodiment, the light emitting from at least one surface of thelight emitting device has an angular full-width at half-maximumintensity (FWHM) less than one selected from the group of: 120 degrees,100 degrees, 80 degrees, 60 degrees, 40 degrees, 20 degrees and 10degrees. In another embodiment, the light emitting from at least onesurface of the light emitting device has at least one angular peak ofintensity within at least one angular range selected from the group of:0-10 degrees, 20-30 degrees, 30-40 degrees, 40-50 degrees, 60-70degrees, 70-80 degrees, 80-90 degrees, 40-60 degrees, 30-60 degrees, and0-80 degrees from the normal to the light emitting surface. In anotherembodiment, the light emitting from at least one surface of the lightemitting device has two peaks within one or more of the aforementionedangular ranges and the light output resembles a “bat-wing” type profileknown in the lighting industry to provide uniform illuminance over apredetermined angular range. In a further embodiment, the shape of thelightguide is substantially cylindrical wherein the light substantiallypropagates through the lightguide in a direction parallel to the longer(length) dimension of the cylindrically shaped lightguide and the lightexits the surface of the lightguide wherein at least 70% of the lightoutput flux is contained within an angular range between and including35 degrees to 145 degrees from the light emitting surface. In a furtherembodiment, the light emitting device emits light from a first surfaceand a second surface opposite the first surface wherein the light fluxexiting the first and second surfaces, respectively, is chosen from thegroup of: 5-15% and 85-95%; 15-25% and 75-85%; 25-35% and 65-75%; 35-45%and 65-75%; and 45-55% and 45-55%. In another embodiment, the firstlight emitting surface emits light in a substantially downward directionand the second light emitting surface emits light substantially in anupward direction. In another embodiment, the first light emittingsurface emits light in a substantially upward direction and the secondlight emitting surface emits light substantially in a downwarddirection.

In one embodiment, a shape of the light emitting region or lightguideand/or a location of the light emitting region on the lightguidecontribute to an angular profile of the light output from the lightemitting device. For example, in one embodiment, the lightguide isconfigured in a wave-like shape and the light emitting regions aredisposed on the sloped regions of the lightguide. In this embodiment,when light extraction features are used that direct 90%, for example, ofthe light out of the lightguide within an angular range of between andincluding 60 to 90 degrees from a surface normal (a high angular outputprofile), the light output from the light emitting device will besubstantially within 30 degrees of the surface angle of the slopedregion. For example, if the light is travelling in a lightguide with adirectional component in the +x direction and an average angle of theslope region (relative to the horizontal, nadir, or other external orinternal surface) is 40 degrees from the horizontal, then the lightoutput from the light emitting device is substantially between andincluding 10 degrees and 70 degrees from the horizontal or between andincluding 40 degrees and 70 degrees from the horizontal if a specularreflector is disposed adjacent the bottom side of the lightguide.

In another embodiment, the lightguide is non-planar and includes a lightemitting region disposed in a valley region or a planar region of thelightguide. In this embodiment, for example, the light emitting regionsare substantially horizontal, vertical, or not sloped relative to aninternal or external reference plane and the light output relative tothe reference is due primarily to the light extraction features asopposed to the curved or non-planar regions. In another embodiment, thelightguide includes one or more light emitting regions on asubstantially planar region, and one or more of the following: a valleyregion, a sloped region, a curved region, a bent region, and a foldedregion. In this embodiment, a relative location of the light output andthe angular profile can be adjusted by placement or orientation of thelight emitting region (or light extraction features along one or moresurfaces of the lightguide or core region).

Method of Manufacturing Light Input/Output Coupler

In one embodiment, the lightguide and light input or output coupler areformed from a light transmitting film by creating segments of the filmcorresponding to the coupling lightguides and translating and bendingthe segments such that a plurality of segments overlap. In a furtherembodiment, the input surfaces of the coupling lightguides are arrangedto create a collective light input surface by translation of thecoupling lightguides to create at least one bend or fold.

Relative Position Maintaining Element

In one embodiment, at least one relative position maintaining elementsubstantially maintains the relative position of the couplinglightguides in the region of the first linear fold region, the secondlinear fold region or both the first and second linear fold regions. Inone embodiment, the relative position maintaining element is disposedadjacent the first linear fold region of the array of couplinglightguides such that the combination of the relative positionmaintaining element with the coupling lightguide provides sufficientstability or rigidity to substantially maintain the relative position ofthe coupling lightguides within the first linear fold region duringtranslational movements of the first linear fold region relative to thesecond linear fold region to create the overlapping collection ofcoupling lightguides and the bends in the coupling lightguides. Therelative position maintaining element may be adhered, clamped, disposedin contact, disposed against a linear fold region or disposed between alinear fold region and a lightguide region.

Packaging

In one embodiment, a kit suitable for providing illumination includes alight source, a light input coupler, and a lightguide.

In one embodiment, the flexible light emitting device can be rolled upinto a tube of a diameter less than one selected from the group of: 6inches, 3 inches, 2 inches and 1 inch. In another embodiment, theflexible light emitting device includes a spring or elastic-basedtake-up mechanism which can draw a portion of the lightguide, the lightemitting region, or the lightguide region inside the housing. Forexample, the light emitting region of the film can be retracted into acylindrical tube when a button on the device is pressed to providesecure, protected storage.

Film Production

In one embodiment, the film or lightguide is an extruded film, aco-extruded film, a cast film, a solvent cast film, a UV cast film, apressed film, an injection molded film, a knife coated film, a spincoated film, or a coated film. In one embodiment, one or two claddinglayers are co-extruded on one or both sides of a lightguide region. Inanother embodiment, tie layers, adhesion promotion layers, materials orsurface modifications are disposed on a surface of or between thecladding layer and the lightguide layer. In another embodiment, one ormore of a lightguide layer, a light transmitting film, a claddingregion, an adhesive region, an adhesion promotion region, and a scratchresistant layer is coated onto one or more surfaces of the film orlightguide.

Separate Coupling Lightguides

In another embodiment, the coupling lightguides are discontinuous withthe lightguide and are subsequently optically coupled to the lightguide.In one embodiment, the coupling lightguides are extruded onto thelightguide, optically coupled to the lightguide using an adhesive,optically coupled to the lightguide by injection molding a lighttransmitting material that bonds or remains in contact with the couplinglightguides and lightguide, thermally bonded to the lightguide, solventbonded to the lightguide, laser welded to the lightguide, sonic weldedto the lightguide, chemically bonded to the lightguide, or otherwisebonded, adhered or disposed in optical contact with the lightguide.

The following are more detailed descriptions of various embodimentsillustrated in FIGS. 1-56. FIG. 1 is a top view of one embodiment of alight emitting device 100 including a light input coupler 101 disposedon one side of a film-based lightguide. The light input coupler 101includes coupling lightguides 104 and a light source 102 disposed todirect light into the coupling lightguides 104 through a light inputsurface 103 including one or more input edges of the couplinglightguides 104. In one embodiment, each coupling lightguide 104includes a coupling lightguide terminating at a bounding edge. Eachcoupling lightguide is folded such that the bounding edges of thecoupling lightguides are stacked to form the light input surface 103.The light emitting device 100 further includes a lightguide region 106including a light mixing region 105, a lightguide 107, and a lightemitting region 108. Light from the light source 102 exits the lightinput coupler 101 and enters the lightguide region 106 of the film. Thislight spatially mixes with light from different coupling lightguides 104within the light mixing region 105 as light propagates through thelightguide 107. In one embodiment, light is emitted from the lightguide107 in the light emitting region 108 due to light extraction features(not shown).

FIG. 2 is a perspective view of one embodiment of a light input coupler200 with coupling lightguides 104 folded in the −y direction. Light fromthe light source 102 is directed into the light input surface 103including input edges 204 of the coupling lightguides 104. A portion ofthe light from the light source 102 propagating within the couplinglightguides 104 with a directional component in the +y direction willreflect in the +x and −x directions from lateral edges 203 of thecoupling lightguides 104 and will reflect in the +z and −z directionsfrom the top and bottom surfaces of the coupling lightguides 104. Thelight propagating within the coupling lightguides is redirected by folds201 in the coupling lightguides 104 toward the −x direction.

FIG. 3 is a top view of one embodiment of a light emitting device 300with three light input couplers 101 on one side of the lightguide region106 including the light mixing region 105, the lightguide 107, and thelight emitting region 108.

FIG. 4 is a top view of one embodiment of a light emitting device 400with two light input couplers 101 disposed on opposite sides of thelightguide 107. In certain embodiments, one or more light input couplers101 may be positioned along one or more corresponding sides of thelightguide 107.

FIG. 5 is a top view of one embodiment of a light emitting device 500with two light input couplers 101 disposed on the same side of thelightguide region 106. The light sources 102 are oriented substantiallywith the light directed toward each other in the +y and −y directions.

FIG. 6 is a cross-sectional side view of one embodiment of a lightemitting device 600 defining a region 604 near a substantially planarlight input surface 603 including planar edges of coupling lightguides104 disposed to receive light from a light source 102. The couplinglightguides include core regions 601 and cladding regions 602. A portionof the light from the light source 102 input into the core region 601 ofthe coupling lightguides 104 will totally internally reflect from theinterface between the core region 601 and the cladding region 602 of thecoupling lightguides 104. In the embodiment shown in FIG. 6, a singlecladding region 602 is positioned between adjacent core regions 601. Inanother embodiment, two or more cladding regions 602 are positionedbetween adjacent core regions 601.

FIG. 7 is a cross-sectional side view of one embodiment of a lightemitting device 3600 including a plurality of input couplers, such astwo light input couplers 101 disposed to couple light into oppositesides of a film-based lightguide 3603 without a core region, and a lowcontact area cover 3601 extending substantially around the light inputcouplers 101 and the film-based lightguide 3603. The low contact areacover 3601 is adhered to itself using an adhesive 3602. In thisembodiment, the low contact area cover 3601 substantially protects thefilm-based lightguide 3603 without the and the coupling lightguideswithin the light input coupler 101. Light 3605 from the light source(not shown) in the light input coupler 101 travels through thefilm-based lightguide 3603, is extracted by a light extraction featureand is directed through the low contact area cover 3601 and through atransmissive spatial light modulator 3604 (or a passive display such asa printed film or graphic, for example) to form a light emitting device3600. In this embodiment, the low contact area cover 3601 substantiallyencapsulates or covers the film-based lightguide 3603 in the x-z plane.

FIG. 8 is a perspective view of one embodiment of a light emittingdevice 11800 disposed adjacent a wall 11801 or other suitable structureor surface. The light emitting device 11800 includes a light inputcoupler 101 disposed to receive electrical power through an electricalpower cable 1003 attached to a power plug 1004. In this embodiment, alightguide 107 includes a core region 601 disposed between two claddingregions 602 and 11805. In this embodiment, the cladding region 602 isadhered to the wall 11801 using a light transmitting adhesive 11806.Light 11803 from the light source 102 in the light input coupler travelsthrough the core region 601, reflectively scatters from a light emittingindicia 1001 light extraction feature, passes through the core region601, passes through the cladding region 11805 and this light 11804 exitsthe light emitting device 11800. In this embodiment, the cladding region11805 has a non-planar surface relief profile 11802 such that its glossis low and specular reflection of ambient light is low (as in the caseof displays including anti-glare coatings or matte paint). Furthermore,in this embodiment, the lightguide 107 substantially transmits ambientlight through the lightguide 107 to the wall 11801 where reflected lightis transmitted back through the lightguide 107 and the color of the wallperceived through the lightguide is substantially the same as the wall11801 without the lightguide 107 coupled to the surface. In thisembodiment, the lightguide 107 of the light emitting device 11801substantially resembles the wall 11801 in color and luminance when thelightguide 107 is not emitting light from the light source 102 and theglare is reduced as with most wall matte paints and textures.

FIG. 9 is a cross-sectional side view of a portion of one embodiment ofa light emitting device 11900 including a lightguide with the coreregion 601 disposed between two cladding regions 602. On one side of thelightguide, a light reflecting film 11901 is optically coupled to thecladding region 602 by a light transmitting adhesive 11806. Aplastically deformable material 11903 is physically adhered to the lightreflecting film 11901 by an adhesive 11902. In this embodiment, thelight emitting device 11900 may be bent to form a new shape due to theplastically deformable material 11903.

FIG. 10 is a cross-sectional side view of a portion of a light emittingdevice 12000 including a lightguide with the core region 601 disposedbetween two cladding regions 602. On one side of the lightguide, aplastically deformable light reflecting film 12001 is optically coupledto the cladding region 602 by the light transmitting adhesive 11806. Inthis embodiment, the plastically deformable light reflecting film 12001reflects light and provides mechanical support for bending the lightemitting device 12000 to a desired shape.

FIG. 11 is a cross-sectional side view of a portion of a light emittingdevice 12002 including a lightguide with the core region 601 disposedbetween the low refractive index cladding region 602 and an air-gapcladding region 12004 including light transmitting adhesive regions12003 in a pattern that couple light out of the lightguide into thelight reflecting film 12001. Light 12006 from the light source and alight input coupler (not shown) is coupled to the light reflecting film12001 by the light transmitting adhesive regions 12003 where the lightreflects back through the light transmitting adhesive regions 12003,through the core region 601, through the cladding region 602, andrefracts and totally internally reflects in a light redirecting element12005. Light 12007 from the light source is totally internally reflectedat the lightguide core region 601 and the air-gap cladding region 12004.

FIG. 12 is a perspective view of a light emitting device 12100 includingthe film-based lightguide 107 formed into a wave-like shape, a firstlight input coupler 12107, and a second light input coupler 12108. Thefilm-based lightguide 107 includes first light extraction regions 12103and second light extraction regions 12104 disposed on positive andnegative sloped regions in the x-y plane, respectively, of thefilm-based lightguide 107. At least one of the first light extractionregions 12103 and the second light extraction regions 12104 includes oneor more light extraction features. In one embodiment, light from thefirst light input coupler 12107 is extracted from the first lightextraction regions 12103 out of the film-based lightguide 107 in a firstpeak luminous intensity direction 12101 with a component in the +y and+x direction. Light from the first light input coupler 12107 isextracted from the second light extraction regions 12104 out of thefilm-based lightguide 107 in a second peak luminous intensity direction12102 with a component in the −y and +x direction. Light from the secondlight input coupler 12108 is extracted from the first light extractionregions 12103 out of the film-based lightguide 107 in a third peakluminous intensity direction 12105 with a component in the −y and −xdirection. Light from the second light input coupler 12108 is extractedfrom the second light extraction regions 12104 out of the film-basedlightguide 107 in a fourth peak luminous intensity direction 12106 witha component in the +y and −x direction. In one embodiment, the lightextraction regions 12104 and 12103 in the angled sections of thewave-like shape of the film-based lightguide 107 direct the light outputthat would typically be about 70 degrees from the nadir (−y direction)on a flat, horizontal lightguide to about 40 degrees from the nadir suchthat there is a lower luminance of the light in the angular glare regionfrom about 45 degrees to about 90 degrees from the nadir (−y direction).

FIG. 13 is a photometric plot of an angular luminous intensity output12109 of the light emitting device 12100 of FIG. 12.

FIG. 14 is a perspective view of a light emitting device 12200 includingthe film-based lightguide 107 that is formed in a wave-like shape, thefirst light input coupler 12107, and the second light input coupler12108. The film-based lightguide 107 includes a light extraction region12202 disposed in the valley inflection region of the curve of thefilm-based lightguide 107. In this embodiment, light from the firstlight input coupler 12107 and light from the second light input coupleris extracted from the light extraction region 12202 out of thefilm-based lightguide 107 with an angular output profile with a peakluminous intensity axis 12203 in the −y direction and the light inputcouplers 101 block a view of high angle (about 45 degrees to 80 degreesfrom the nadir) light from the light extraction region 12202 to reduceglare.

FIG. 15 is a perspective view of a light emitting device 12300 includingthe film-based lightguide 107 formed into a wave-like shape, bendableside support rails 12301, the first light input coupler 12107, and thesecond light input coupler 12108. In this embodiment, the bendable sidesupport rails 12301 substantially support the film-based lightguide 107and have a yield strength of 50 psi such that the side support rails12301 can be bent or configured to provide curved or angular lightemitting shapes in the lightguide disposed between them.

FIG. 16 is a perspective view of a light emitting device 12400 includingthe film-based lightguide 107 formed into a wave-like shape, aplastically deformable mesh support 12401 physically coupled to thefilm-based lightguide 107, and the light input coupler 101. In thisembodiment, the plastically deformable mesh support allows the film tobe shaped and bent into a desired form (such as a wave-like shape,arcuate shape, angled shape, or “L”-shape, for example).

FIG. 17 is a perspective view of a light emitting device 12402 includingthe film-based lightguide 107 formed into a wave-like shape, a first setof plastically deformable wire supports 12403 physically coupled to thefilm-based lightguide 107, a second set of plastically deformable wiresupports 12404 oriented orthogonal to the first set of plasticallydeformable wire supports 12403 and physically coupled to the film-basedlightguide 107, and the light input coupler 101. In this embodiment, anaverage pitch of the second set of plastically deformable wire supports12404 in the x direction is larger than an average pitch of the firstset of plastically deformable wire supports 12403 in the z direction. Inthis embodiment, the plastically deformable wire support configurationfacilitates a flexural modulus and/or a yield strength to be less in aplane including the first set of plastically deformable wire supports12403 (y-z plane) than a flexural modulus and/or a yield strength in aplane including the second set of plastically deformable wire supports12404 (x-y plane) and the yield strength is anisotropic. As shown inFIG. 17, it is easier to bend the film-based lightguide 107 physicallycoupled to the plastically deformable wire supports 12403 and 12404 inthe y-z plane than the x-y plane.

FIGS. 18 and 19 are perspective views of one embodiment of a lightemitting device including a cladding layer 12502 that can be peeled backand a light extraction region 12501 that can be placed on the coreregion 601 of the lightguide. The lightguide further includes thecladding region 602 optically coupled to an opposite surface of the coreregion 601. As shown in FIG. 18, the cladding layer is peeled back inthe +z and +x direction from the core region 601 and the lightextraction region 12501 is placed onto the core region 601. FIG. 19illustrates the cladding layer 12502 being laid on top of the lightextraction region 12501 and the core region 601. Light 12601 from thelight input coupler 101 travels through the core region 601, isreflected from the light extraction region 12501 and is directed out ofthe light emitting device 12500 with a component in the −z direction.

FIG. 20 is a bottom view of one embodiment of a light emitting device12700 disposed substantially horizontally (x direction). The light inputcoupler 101 is positioned within a support surface or structure, such aswithin a ceiling 12704, and the lightguide 107 extends below the ceiling12704 in the −x direction. The lightguide 107 includes one or more ofthe following: one or more rectangular removable and replaceable lightextraction regions 12501, one or more elliptical removable andreplaceable light extraction regions 12701, one or more substantiallylinear removable and replaceable light extraction regions 12702, and acollection of a plurality of removable and replaceable light extractionregions 12703, such as an array of removable and replaceable lightextraction regions 12703, disposed between the core region and aremovable cladding regions 12707 in one or more sections of thelightguide 107. In this embodiment, the film-based lightguide 107 isdraped across the ceiling and includes apertures 12705 through whichhooks 12706 or other suitable fasteners connect the lightguide 107 tothe ceiling. In this embodiment, when one wishes to change the lightoutput pattern of light emitted from the light emitting device 12700,the lightguide 107 can be disconnected from the hooks 12706 and theremovable cladding regions 12707 can be removed (or peeled back) inregions where the light extraction region is to be removed, replaced, orchanged to a light extraction region with a different shape, extractionpattern, optical output, color, and/or light extraction feature with adifferent angular output, for example.

FIG. 21 is a cross-sectional side view of one embodiment of a lightemitting device 12800 disposed underneath a ceiling tile 12801. Lightfrom the light input coupler 101 physically coupled to a ceiling tilerail support 12802 travels through the film-based lightguide 107 andexits in a downward direction 12803 away from the ceiling tile 12801. Inanother embodiment, the light exits the lightguide with an angularcomponent in the downward (−z) direction and upward (+z) directiontoward the ceiling tile 12801 and reflects back downward through thelightguide 107 and continues with a downward (−z) directional component.In the embodiment shown, two light input couplers 101 couple light intothe lightguide 107 from opposite sides. A significant portion of ambientlight 12804 incident on the lightguide 107 passes through the lightguide107, reflects back from the ceiling tile 12801, and passes back throughthe lightguide 107. In one embodiment, an average color and luminance ofthe ceiling tile 12801 disposed above non-emitting regions of thelightguide 107 (when the light sources in the light input couplers 101are turned off) measuring through the lightguide 107 normal to thesurface is substantially the same as an average color and luminance ofthe neighboring ceiling tiles 12801 when illuminated from a D65 standardwhite light source of substantially the same illuminance and color. Inanother embodiment, an average color and luminance of the ceiling tile12801 disposed above the lightguide 107 (when the light sources in thelight input couplers 101 are turned off) measuring through thelightguide 107 normal to the surface is substantially the same as anaverage color and luminance of the neighboring ceiling tiles 12801 whenilluminated from ambient light of substantially the same illuminance andcolor. In one embodiment, an ASTM D1003 luminous transmittance of thelightguide in the regions surrounding the light extraction features isgreater than 70% and the spectral transmission between 400 nm and 700 nmis within +/−10%.

FIG. 22 is a perspective view of one embodiment of a light emittingdevice 12900 including the film-based lightguide 107 curved in anarcuate shape in the +z direction between two light input couplers 101that are separated by an adjustable extension guide 12901. The lightemitting device 12900 includes adjustable extension guides 12901oriented in the x direction on both sides of the lightguide 107 in the ydirection. In this embodiment, a separation between the two light inputcouplers 101 is low and an arc of the lightguide 107 has a first averageradius of curvature 12903 and a light output of the light emittingdevice 12900 has a first angular light output 12902. In one embodiment,the adjustable extension guide 12901 includes two extruded aluminumprofiles with substantially parallel guide surfaces that align such thatthe two guides can move closer (such as by sliding, for example)together or further apart and guide the light input couplers apartwithout torsion or rotation relative to each other.

FIG. 23 is a perspective view the light emitting device 12900 of FIG. 22with the adjustable extension guide 12901 extended in the x directionsuch that the light input couplers 101 are separated by a largerdistance and an arc of the lightguide 107 has a second radius ofcurvature 12905 larger than a first average radius of curvature 12903shown in FIG. 22 and a second angular light output 12904. The secondangular output 12904 of the light emitting device 12900 is changedrelative to the first angular output 12902 of the light emitting device12900 of FIG. 22 due to a change in shape of the lightguide 107.

FIG. 24 is a perspective view the light emitting device 12900 of FIG. 22with the adjustable extension guide 12901 extended in the x directionand the film having an arc that extends in the −z direction. The lightinput couplers 101 are separated by a larger distance and the arc of thelightguide 107 has a third average radius of curvature 12907 larger thanthe first average radius of curvature 12903 shown in FIG. 22 and with adirection component in the −z direction. The arc of the lightguide 107in this embodiment results in a third angular light output 12906different than the first angular output 12902 of FIG. 22 and the secondangular output 12904 of FIG. 23.

FIG. 25 is a perspective view of one embodiment of a light emittingdevice 13200 including the film-based lightguide 107 formed into awave-like shape between two light input couplers 101 that are separatedby guide rails 13202 on both sides of the lightguide 107 in the ydirection. Lightguide positioning rods 13201 are disposed between guiderails 13202 to position the film. In one embodiment, one or more of thelightguide positioning rods 13201 may be moved and positioned in adifferent location along the guide rails 13202. In this embodiment, thelightguide positioning rods 13201 are positioned such that thelightguide positioning rods 13201 clamp a region of the lightguide 107between the neighboring lightguide positioning rods and substantiallymaintain the position of the region and hold a shape of the lightguide107. The shape of the lightguide 107 can be changed by sliding (andlocking down by a bolt or suitable fastener, for example) the pairs oflightguide positioning rods 13201 along the guide rails 13202 and/or byloosening a hold on the lightguide by separating the pairs of lightguidepositioning rods 13201 and feeding the lightguide 107 between the pairof rods.

FIG. 26 is a perspective view of one embodiment of a light emittingdevice 13300 including the film-based lightguide 107. The film-basedlightguide 107 is held in a wave-like shape by the lightguidepositioning rods 13201 with ends physically coupled to guide rails 13202on opposite sides of the film-based lightguide 107. The guide rails13202 are physically coupled to the light input coupler 101 and a railcoupler 13305. The film-based lightguide 107 includes light emittingregions 108 oriented in an average first direction 13301 at a firstangle 13307 from a reference direction 13303 parallel to the x axis.Light from the light input coupler 101 travels within the lightguide 107and exits the lightguide 107 in the light emitting region 108 in asecond direction 13302 with a first angle of peak luminous intensity13304 from a reference direction 13303 parallel to the x axis for thelight emitting region 108. In this embodiment, the light emittingregions repeat and are substantially similar in size, shape andorientation, the first angle of peak luminous intensity 13304 of thelight emitting region 108 is the same as the angle of peak luminousintensity of the light emitting device 13300. The angle of the peakluminous intensity for the light emitting region 108 may vary across thelight emitting region 108 and a first angle of the peak luminousintensity 13304 for the light emitting region 108 is an angle of thepeak luminous intensity for the total light emitted from the particularlight emitting region 108. In one embodiment, the lightguide positioningrods 13201 can be repositioned by sliding the lightguide positioningrods 13201 along the guide rails 13202 such that the first angle of peakluminous intensity 13304 can be increased or decreased for one or morelight emitting regions. In a further embodiment, the x axis is in thevertical direction and the light emitting device is a light fixturemounted vertically such that the light output can be adjusted bychanging the relative positions, orientations, and/or number oflightguide positioning rods and/or the shape of the film-basedlightguide passing between the rods. For example, in one embodiment, anangle of peak luminous intensity for the light emitting device isadjusted by pulling a cord that brings the lightguide positioning rodscloser together. In another embodiment, the light emitting device has asecond light input coupler on the opposite edge of the lightguide with asecond angle of peak luminous intensity for the light from the secondlight input coupler. In another embodiment, the guide rails areextendable.

FIG. 27 is a perspective view of one embodiment of the light emittingdevice 13300 of FIG. 26 wherein the spacing between the pairs of thelightguide positioning rods 13201 has been increased such that thefilm-based lightguide 107 is formed in a wave-like shape with a largerpitch and with light emitting regions 108 oriented in an average thirddirection 13404 at a third angle 13402 from the reference direction13303 parallel to the x axis. The film-based lightguide 107 is held in awave-like shape by the lightguide positioning rods 13201 clamping thelightguide 107 between the lightguide positioning rods at regularlyspaced locations. Light from the light input coupler 101 travels withinthe lightguide 107 and exits the lightguide 107 in the light emittingregion 108 in a fourth direction 13401 with a second angle of peakluminous intensity 13403 from the reference direction 13303 parallel tothe x axis. The second angle of peak luminous intensity 13403 shown inFIG. 27 is smaller than the first angle of peak luminous intensity 13304shown in FIG. 26 and more light is directed toward the +x direction(toward the ceiling, for example, if the light emitting device isoriented vertically).

FIG. 28 is a perspective view of one embodiment of a light emittingdevice 13500 including light input couplers 101 and the film-basedlightguide 107 with adjustable tension rails 13501 physically coupled tolightguide positioning rods 13201 with light output from substantiallyone side of the film based lightguide 107. In this embodiment, the light13503 is substantially emitted with a component in the +x direction (updirection, for example). The angle of peak luminous intensity can beadjusted by moving an intersection location and an angle of intersectionof the adjustable tension rails 13501 and a location of the lightguidepositioning rods 13201 on the adjustable tension rails 13501 using theadjustment bolts 13502. Thus, an angular light output and spatiallocations of the light emitting regions 108 of the film-based lightguide107 can be adjusted to a variety of shapes. In a further embodiment, alocation of one or more light emitting regions 108 is reconfigurable byusing removable and replaceable light extraction regions or filmsincluding light extraction regions.

FIG. 29 is a perspective view of one embodiment of a light emittingdevice 13600 including light input couplers 101 and the film-basedlightguide 107 with the adjustable tension rails 13501 physicallycoupled to lightguide positioning rods 13201 with light output from bothsides of the film based lightguide 107. In this embodiment, light 13503is substantially emitted with a component in the +x direction (updirection, for example) and light 13601 is emitted with a component inthe −x direction. The angle of peak luminous intensity can be adjustedby moving the intersection location and the angle of intersection of theadjustable tension rails 13501 and the location of the lightguidepositioning rods 13201 on the adjustable tension rails 13501 using theadjustment bolts 13502. Thus, the angular light output and spatiallocations and orientations of the light emitting regions 108 of thefilm-based lightguide 107 can be adjusted for a desired angular lightoutput profile or location of light emitting regions.

FIG. 30 is a perspective view of one embodiment of a light emittingdevice 13700 including light input couplers 101 and the film-basedlightguide 107 with flexible adjustment tubes 13701 extending throughapertures 13702 in the film based lightguide 107. In this embodiment,the shape of the film-based lightguide 107 (and the angular light outputprofile) can be varied by bending the flexible adjustment tubes 13701physically coupled to the light input couplers 101. In one embodiment,the flexible adjustment tubes have shapes different from each other suchthat the film-based lightguide is oriented at an angle (such as orientedat an angle in the x-z plane to the orientation of the film-basedlightguide exiting the light input coupler). In one embodiment, theflexible adjustment tubes are plastically deformable by hand and enableshaping of the lightguide or light emitting film without the use oftools. In another embodiment, the light emitting device includesflexible adjustment tubes that physically support the second light inputcoupler such that the second light input coupler is suspended andcarries the electrical wires within the tube.

FIG. 31 is a perspective view of one embodiment of an elongated lightemitting device 13800 including the light input coupler 101 and thefilm-based lightguide 107 with a lightguide film adjustment mechanism13806. The lightguide film adjustment mechanism includes two drawstrings13803 and 13804 threaded through a ring 13802. The drawstring 13804 isconnected to a middle region 13807 of the film-based lightguide using afilm attachment device 13805. In one embodiment, the film attachmentdevice 13805 includes a clip, clamp, or aperture region in thefilm-based lightguide, or other attachment device to connect thedrawstring to the film. The drawstring 13803 is similarly attached tothe film-based lightguide 107 in the middle region 13807 on the oppositeside of the film using a second film attachment device (not shown). Thelight from the light input coupler 101 travels through the film-basedlightguide 107 and light 13801 exits in the light emitting regions 108.This light 13801 exits the sides of the film-based lightguide 107 with afirst full-angular widths from the nadir (−x direction) at half maximumluminous intensity in the x-y plane due to the low extraction anglesfrom the light emitting regions 108 and the orientation of thefilm-based lightguide 107. For example, in one embodiment, the firstfull-angular width from the nadir at half maximum intensity is within arange between and including 10 and 60 degrees from the nadir. When thedrawstrings 13804 and 13803 are pulled, the middle region 13807 of thefilm-based lightguide 107 are pulled upward, changing the shape of thelightguide as shown in FIG. 32.

FIG. 32 is a perspective view of the light emitting device 13800 of FIG.31 with the drawstrings 13803 and 13804 pulled such that the middleregion 13807 of the film-based lightguide is pulled closer to the lightinput coupler 101 and portions of the sides of the film-based lightguide107 and the light emitting regions 108 are oriented at larger anglesfrom the nadir. The light 13901 emitting from the light emitting device13800 with the drawstrings pulled has second full-angular widths fromthe nadir (−x direction) at half maximum luminous intensity larger thanthe first full angular widths. Thus, by pulling on the drawstrings, theangular profile (width) of the light emitting device is widened in afirst output plane (x-y plane). For example, in one embodiment, thesecond full angular widths are within a range between and including 30and 70 degrees from the nadir. The light emitting surface area isdetermined by the light extracting surface features and the lightextracting surface feature type, size, location, and pattern will affectthe angular output from the light emitting device and can be designed toallow for optimal control (such as large angular adjustment with minimalglare from the side walls, for example).

FIG. 33 is a top view of one embodiment of a light emitting device 14000including the light input coupler 101 including the coupling lightguides104, the film-based lightguide 107, and a light output coupler 14002including coupling lightguides 104. The light from the light source 102in the light input coupler 101 travels through the coupling lightguides104 of the film-based lightguide 107. A portion of the light from thelight source 102 is emitted from the film-based lightguide 107 in thelight emitting region 108 and a portion of the light travels through thefilm-based lightguide 107 and into the light output coupler 14002including the folded array of coupling lightguides 104 arranged todirect light onto a specular reflector 14001. The specular reflector14001 may be disposed adjacent to or optically coupled to the ends ofthe coupling lightguides 104. The light reaching the specular reflector14001 is reflected back into the coupling lightguides 104 of the lightoutput coupler 14002 and a portion of this light exits the lightemitting device 14000 through the light emitting region 108. In thisembodiment, the light output coupler 14002 and the specular reflector14001 serve to recycle the light back into the lightguide where there isanother opportunity to be extracted. In one embodiment, the recycledlight increases one or more of the following: optical efficiency,spatial luminance uniformity in the light emitting region, spatial coloruniformity in the light emitting region, angular full-width at halfmaximum luminous intensity of the light emitted from the light emittingregion, and the number of angular peak regions of the angular lightoutput profile. For example, in one embodiment, the light extracted inthe light emitting region from light propagating in the +x direction asshown in FIG. 33 has an angular peak of about 70 degrees from the zdirection (out of the page) toward the +x direction. The light extractedin the light emitting region from light propagating in the −x direction(after reflecting from the reflector) has an angular peak of about 70degrees from the z direction (out of the page) toward the −x direction.Thus, by recycling the light in this manner, the light output has twoangular peaks in the x-z plane at +70 and −70 degrees, providing asymmetric and a more optically efficient light emitting device.

FIG. 34 is a perspective view of one embodiment of a light emittingdevice 14100 with a longer dimension in the y direction than the xdirection including two sets of coupling lightguides 104 on oppositesides of the film-based lightguide 107 that are folded under and stackedadjacent each other. The input edges 204 of the coupling lightguides 104are disposed to receive light from the light source 102. In thisembodiment, a single light source (or an array or arrangement of lightsources) is disposed to couple light 14102 initially travelling in the+y direction into a first set of coupling lightguides 104 and thedirection is changed due to the fold in the coupling lightguides 104 totravel in the +x direction through the film-based lightguide 107. Light14101 exits the film-based lightguide 107 from the light emitting region108 with a directional component in the −z direction. In thisembodiment, a single light source can be employed to provide a moreuniform spatial luminance profile in the light emitting region of thefilm-based lightguide or provide two angular luminous intensity peaks(in the x-z plane) due to the light propagating in opposite directionswithin the lightguide. By using coupling lightguides that are foldedunderneath the film-based lightguide, the coupling lightguides (andpossibly the light source) can be substantially disposed within a volumeencapsulated by the curved film-based lightguide. Thus, in thisembodiment, the light emitting device requires less volume than one withthe coupling lightguides exterior to the volume encapsulated by thefilm-based lightguide.

FIG. 35 is a perspective view of one embodiment of an elongated lightemitting device 14200 including the light input coupler 101 and thefilm-based lightguide 107 with two lightguide positioning rods 14202 and14203. The light from the light input coupler 101 is directed into thelightguide travelling in the +y direction and is emitted from thelightguide in the light emitting region 108 substantially in thevertical direction downward (−x direction). The light 14201 exiting thelight emitting region has a directional component in the −x direction(downward toward the nadir). For example, in one embodiment, more than80% of the light emitted from the light emitting device is within oneangular range selected from the group of: 50 degrees, 40 degrees, 30degrees, and 20 degrees from the nadir (−x direction).

FIG. 36 is a perspective view of the light emitting device 14200 of FIG.35 wherein the relative positions of the lightguide positioning rods14202 and 14203 have been changed (lightguide positioning rod 14202 istranslated in the −x direction) and a shape and a position of thefilm-based lightguide 107 and a position of the light emitting region108 is changed relative to the embodiment illustrated in FIG. 35. As thelightguide positioning rod 14202 is translated in the −x direction, theend region of the film-based lightguide 107 and the light emittingregion 108 translate upwards (+x direction) and around the lightguidepositioning rod 14203. As a result, a significant portion of the lightemitted from the light emitted device exits the light emitting region108 with a directional component upwards (in the +x direction). Bytranslating the position of lightguide positioning rod 14202 thedirectional light output profile of the light emitting device is changedfrom substantially directing light downwards (FIG. 35) to directing morelight 14301 upwards (FIG. 36). In one embodiment, the lightguidepositioning rods are attached to a rail, suspended from the ceiling, orotherwise physically coupled to a supporting device that allows therelative location of one or more lightguide position rods (and/or thelight input coupler) to be changed. Additionally, the light extractionfeature pattern, size, type, and/or location can be adjusted to controlthe relative light output. For example, as shown in FIG. 36, a portionof the light emitting region 108 directly above the lightguidepositioning rod 14203 may emit light with a substantially horizontal (+ydirection) component that could cause glare. Thus, by adjusting thelocation of the light extraction features in the light emitting region108 to create two separate light emitting regions on either side of thelightguide positioning rod 14203 with a non-light emitting regionbetween, when the lightguide positioning rod 14203 is in the locationshown in FIG. 36, an absence of the light emitting region directly abovethe light emitting rod could reduce or eliminate glare light with adirectional component in the horizontal direction (+y direction) atangles such as 55 to 85 degrees from the nadir (−x direction), forexample.

FIG. 37 is a side view of one embodiment of a light emitting device14400 including the film-based lightguide formed into a bulbous shapewith coupling lightguides 104 twisted and stacked together and disposedto receive light from the light source 102. Light 14401 from the lightsource 102 exits the film-based lightguide 107 in the light emittingregion 108. In one embodiment, the light extraction features extract atleast 80% of the extracted light within an angular range greater than 60degrees from the normal to the film-based lightguide at the lightextraction feature. In this example, light propagating downward in alight emitting device as shown in FIG. 37 will emit the light 14401 withdirectionality substantially downward (−x direction). This enables thelight emitting device to be optically efficient at directing light witha directional component in one direction, such as directing the lightthrough the light emitting region 108 in the −x direction as shown inFIG. 37. This directionality is advantageous when the light emittingdevice is a replacement bulb for a downlight or is a downlight lightfixture. Other shapes may also be used such as conical, polygonal,arcuate, or other geometric or non-geometric shapes. For example, whenthe light emitting region is substantially oriented along the surface ofa shape that is substantially vertical or within a small angle from thevertical (such as in the case of a conical shape that is long relativeto its diameter), most of the light output (80% for example) may becontained within a small angular range (such as 40 degrees) from thevertical or nadir (−x direction as shown in FIG. 37). In one embodiment,a lower central region 14403 of the film-based lightguide does notinclude light extraction features. In another embodiment, the light fromthe light emitting device 14400 is emitted into a large angular range(such as radially in all directions in the y-z plane and at anglesgreater than 2 degrees from the +x axis).

FIG. 38 is a top view of one embodiment of a light emitting device 14500including coupling lightguides 104 and output coupling lightguides 14501disposed to recycle light back to the input coupling lightguides. Thelight source 102 is disposed to direct light through a first region ofthe light input surface 103 of the input coupling lightguides 104 andthe output coupling lightguides 14501 are disposed on an oppositesurface of the film-based lightguide 107 to receive a first portion oflight from within a film-based lightguide 107 and direct this lightthrough output coupling lightguides 14501 to a second region of thelight input surface 103 on the input coupling lightguides 104. Light14506 from the light source 102 is directed into the first set of inputcoupling lightguides 104 and travels through the film-based lightguide107 and is not redirected out of the film-based lightguide 107 by lightextraction features in the light emitting region 108 in the first pass.The light 14506 is then coupled into the output coupling lightguides14501 where the light travels in a waveguide condition and is folded(14503, 14504, and 14505) three times before entering into a secondregion of the input surface of the input coupling lightguides 104. Light14507 from the light source 102 travels through the input couplinglightguides 104 and film-based lightguide 107. On the opposite side ofthe film-based lightguide 107 the light is reflected back from lightreflecting features 14502 into the light emitting region 108 where thelight is recycled. The light may encounter a light extraction featurewithin the light emitting region 108 that redirects the light out of thefilm-based lightguide 107 and the light emitting device 14500. In oneembodiment, the light reflecting features include triangular cuts withabout 90 degree apex angles disposed to totally internally reflect lightwithin a first acceptance angle from within the film-based lightguide.

FIG. 39 is a perspective view of one embodiment of a light emittingdevice 14600 including the light input coupler 101 and the film-basedlightguide 107 hanging downward such that a substantially verticalregion of the film-based lightguide includes a light emitting region 108that emits light 14201. The light 14201 exiting the light emittingregion 108 has a directional component in the −x direction (downwardtoward the nadir). In one embodiment, the light exiting the lightguidehas a luminous intensity less than 300 candelas at 55 degrees from thenadir (−x direction) in the x-y plane. The light may be emitted fromeither or both surfaces of the substantially vertical region of thefilm-based lightguide in the light emitting region. For example, in oneembodiment, more than 80% of the light emitted from the light emittingdevice is within one angular range selected from the group of: 50degrees, 40 degrees, 30 degrees, and 20 degrees from the nadir (−xdirection).

FIG. 40 is a perspective view of one embodiment of a light emittingdevice 14700 including the light input coupler 101 which couples lightinto a film-based distribution lightguide 1501. The light 14705 from thelight source within the light input coupler 101 travels through thedistribution lightguide 1501 with an optical axis substantially parallelto the +y axis and is coupled into a first output coupling lightguide14701 where the light travels in a waveguide condition with adirectional component in the −x direction and is redirected by lightextraction features such that the light exits the first output couplinglightguide 14701 in the light emitting region 108. Light transmittingregions 14707 are the regions of the distribution lightguide 1501 thatare optically coupled to the light receiving regions 14708 of the outputcoupling lightguides 14701 and 14702. The light 14706 from the lightsource within the light input coupler 101 travels through thedistribution lightguide 1501 with an optical axis substantially parallelto the +y axis and is coupled into the second output coupling lightguide14702 where the light travels in a waveguide condition with adirectional component in the −x direction and is redirected by lightextraction features such that the light exits the second output couplinglightguide 14702 through the light emitting region 108. A width 14703 ofthe light receiving region 14708 of the first output coupling lightguide14701, in the direction (z direction) substantially perpendicular to theoptical axis (+y direction) of the light in the distribution lightguide1501, that is optically coupled to the distribution lightguide 1501 isless than a width of the distribution lightguide 1501 in the zdirection. By using the light receiving region 14708 with the smallerwidth 14703 than the output coupling lightguide 14701 in the lightemitting region 108, less light is coupled into the first outputcoupling lightguide 14701 than if the width 14703 of the light receivingregion 14708 was the full width of the first output coupling lightguide14701 in the light emitting region 108. This, for example, can enableone to compensate for the higher flux of light closer to the lightsource such that the light flux exiting the light emitting regions ismore uniform. Alternatively, the width 14703 of the output couplinglightguide 14701 can be used to control the light output for otherreasons such as highlighting a region of a room. The width of the lightreceiving region 14708 of the second output coupling lightguide 14702 isthe full width 14704 of the second output coupling lightguide and anoutput coupling efficiency of the second output coupling lightguide14702 is greater than an output coupling efficiency of the first outputcoupling lightguide 14701. As shown, a thickness (x direction in theregion of optical coupling) of the output coupling lightguides 14701 and14702 is greater than a thickness of the distribution lightguide 1501such to enable more light to be coupled into the output couplinglightguides 14701 and 14702. The location of the light transmittingregion 14707 is further along the distribution lightguide 1501 (in thedirection of the optical axis) enabling the extraction of light furtherfrom the light input coupler 101. In one embodiment, a location and anorientation of the light output couplers may be changed by peeling backthe light output couplers and reapplying the light output couplers tothe distribution lightguide in different locations.

FIG. 41 is a side view of one embodiment of a light emitting device14800 including the light input coupler 101 which couples light into thedistribution lightguide 1501 formed from a film. An output couplinglightguide 14801 is optically coupled to the distribution lightguide1501 using strip coupling lightguides 14802 separated by fold regions14803. The light input coupler 101 and distribution lightguide 1501 aresimilar to those shown in FIG. 40 from a different viewpoint. Light14805 from the light input coupler 101 travels with a directionalcomponent in the +y direction (out of the page) through the distributionlightguide 1501 and is optically coupled into the strip couplinglightguide 14802 formed at the edge of the output coupling lightguide14801. This light 14805 travels with a directional component in the −xdirection within the output coupling lightguide 14801 and exits 14804the output coupling lightguide 14801 through the light emitting region108 with a directional component in the −x direction. As shown in FIG.41, the total width of the strip coupling lightguides 14802 that areoptically coupled to the distribution lightguide 1501 is less than thewidth of the distribution lightguide 1501 and less than the width of theoutput coupling lightguide 14801 in the z direction. The width andnumber of the strip coupling lightguides 14802 can control an amount oflight coupled into the output coupling lightguide 14801. Also, bydistributing the coupling regions (where the strip coupling lightguides14802 are optically coupled to the distribution lightguide 1501), aspatial luminance uniformity of the light 14804 emitted from the outputcoupling lightguide 14801 is typically increased relative to theuniformity of an output coupling lightguide that receives light from oneside with the width of the output coupling lightguide significantlygreater than a width of the coupling region. The folds allow for anincreased light emitting surface relative to a non-folded outputcoupling lightguide and can offer increased rigidity or increasedflexural modulus in the x-y plane for the output coupling lightguide.

FIG. 42 is a perspective view of one embodiment of a light emittingdevice 14900 including the light source 102 disposed to couple lightinto an array of lightguide strips 14901 including light emittingregions 108. Light 14902 from the light source 102 travels in awaveguide condition within the lightguide strips and exits in the lightemitting regions 108. As shown in FIG. 42, the light 14902 exits from atop surface and an opposing bottom surface of the lightguide strips14901 due to light extraction features (not shown) within the lightemitting regions 108. In one embodiment, the orientation and/or theshape of the lightguide strips can be controlled to produce a desiredlight output profile. For example, as shown, the light emitting device14900 emits light in a range of angles substantially within ahemispherical output with an axis parallel to the +x axis. By orientingthe strips substantially parallel to the x axis in the +x direction, 80%of the light output can be contained within an angular range 40 degreesfrom the +x axis, for example. Different shapes and orientations of thestrips can produce a range of angles in different direction.

FIG. 43 is a perspective view of one embodiment of a light emittingdevice 15000 including a tubular light input coupler 15001 (includingfolded coupling lightguides bent in a circular shape and a light source)extending from a tubular film-based lightguide 15002 with outputcoupling lightguides 15003 on an opposite end. Light from the tubeshaped light input coupler 15001 is coupled into the tubular film-basedlightguide 15002 and is output into the output coupling lightguides15003 where the light 14902 exits from the light emitting region 108. Inthe embodiment shown in FIG. 43, the tubular film-based lightguide 15002can function as a distribution lightguide to transfer, in certainembodiments over distances of many meters, the light from the lightinput coupler 15001 to the output coupling lightguides 15003. In thisembodiment, for example, the light source may be disposed further fromthe output coupling lightguides as in the case where the light source isdisposed near the ceiling, and the film-based lightguide is suspendedfrom the ceiling and has light emitting output coupling lightguides onan opposite end forming a type of chandelier that could be circular,linear, or arranged as an arcuate or wave-like shape, or other suitableshape that can be formed from a film or arrangement of light emittingsections from a film.

FIG. 44 is a perspective view of one embodiment of a light emittingdevice 15100 including the light input coupler 101 and a plasticallydeformable film-based lightguide 15101. Light 15102 from the plasticallydeformable film-based lightguide 15101 is emitted from a substantiallyplanar surface (parallel to the x-z plane) and the light 15102 from thelight input coupler 101 is emitted from the light emitting region 108within a first angular range from the +x axis. For example, in oneembodiment, at least 80% of the light emitted from the light emittingdevice is emitted within 40 degrees from the +x axis. Light 15103 fromthe light input coupler 101 is emitted from the light emitting region108 at a second angle from the x-z plane and a third angle from the x-yplane.

FIG. 45 is a perspective view of the light emitting device 15100 of FIG.44 wherein the plastically deformable film-based lightguide 15101 isfolded into a shape with a wave-like cross-sectional profile in the y-zplane. Light 15202 exits the plastically deformable film-basedlightguide 15101 in the light emitting region 108 from either side ofthe plastically deformable film-based lightguide 15101 with directionalcomponents in the +y and −y directions. In this embodiment, theplastically deformable film-based lightguide 15101 can be folded or alateral dimension in the z direction can be reduced such that an angularlight output profile can be changed. The light 15203 has an angularcomponent in the y-z plane that is increased due to a surface profilecreated due to bends in the light emitting region 108. An angular widthfull-width at half maximum luminous intensity of the light exiting theemitting device 15100 of FIG. 45 is increased in the y-z plane relativeto the flat, plastically deformable, film-based lightguide of FIG. 44due to bends. In another embodiment, the lateral dimension in the xdirection of a plastically deformable, film-based lightguide is reducedby folding or bringing two or more regions of the lightguide closertogether.

FIG. 46 is a cross-sectional side view of one embodiment of a lightemitting device 15300 including two sets of coupling lightguides 104 onopposite sides of the film-based lightguide 107 that are foldedunderneath the film based lightguide 107 and stacked adjacent eachother. The film-based lightguide is formed into a hemisphere-like shape.The input edges 204 of the coupling lightguides 104 are disposed toreceive light from the light source 102. In this embodiment, a singlelight source (or an array or arrangement of light sources) is disposedto couple light 15302 initially travelling with a directional componentin the +y direction (into the page) into the first set of couplinglightguides 104 and a direction is changed due to a fold in the couplinglightguides 104 such that the light travels with a directional componentin the −x direction through the film-based lightguide 107. The light15303 from the light source 102 initially travels with a directionalcomponent in the +y direction (into the page) into a second set ofcoupling lightguides 104 and a direction is changed due to a fold in thecoupling lightguides 104 such that the light travels with a directionalcomponent in the +x direction through the film-based lightguide 107.Light 15301 exits the film-based lightguide 107 with a directionalcomponent in the −z direction. In this embodiment, the light propagatingin opposite directions within the lightguide provides a more uniformspatial luminance profile in the light emitting region of the film-basedlightguide and/or provides two angular luminous intensity peaks (in thex-z plane). In one embodiment, the coupling lightguides and light sourceare not disposed within the volume substantially bounded by thefilm-based lightguide.

FIG. 47 is a cross-sectional side view of one embodiment of a lightemitting device 15400 including the film-based lightguide 107 in theshape of a dome with a camera 15401 disposed within the dome. The lightemitting device 15400 includes two sets of coupling lightguides 104 onopposite sides of the film-based lightguide 107 that are foldedunderneath the film-based lightguide 107 and stacked adjacent eachother. The film-based lightguide is formed into a hemisphere-like shape.The input edges 204 of the coupling lightguides 104 are disposed toreceive light from the light source 102. In this embodiment, the singlelight source (or an array or arrangement of light sources) is disposedto couple light 15402 initially travelling with a directional componentin the +y direction (into the page) into the first set of couplinglightguides 104 and a direction is changed due to a fold in the couplinglightguides 104 to travel with a component in the −x direction throughthe film-based lightguide 107. The light 15402 exits the film-basedlightguide 107 after being redirected from a light extraction feature15405 disposed on the inner surface of the film-based lightguide 107.The light 15403 from the light source 102 initially travels with adirectional component in the +y direction (into the page) into thesecond set of coupling lightguides 104 and a direction is changed due tothe fold in the coupling lightguides 104 to travel with a directionalcomponent in the +x direction through the film-based lightguide 107. Thelight 15403 exits the film-based lightguide 107 after being redirectedfrom the light extraction feature 15405 disposed on an inner surface ofthe film-based lightguide 107. In general, light 15404 exits thefilm-based lightguide 107 with a directional component in the −zdirection. The camera 15401 is disposed on an opposite side of thefilm-based lightguide 107 as the light emitting surface 15406 and isdisposed to receive light external to the light emitting device 15400that passes through the film-based lightguide 107 and reaches the camera15401. The size, shape, number, location, and type of light extractionfeatures 15405 affect the perceived uniformity of a light emittingsurface 15406 of the light emitting device 15400 and the transmission oflight 15407 to the camera. For example, in one embodiment, the thinfilm-based lightguide 107 permits the use of very small light extractionfeatures 15405 separated by a distance such that when viewed, forexample, at a distance of 3 feet away, appear continuous despite therebeing a gap between them. The gap allows clear, undiffused light to passthrough the film-based lightguide 107 to the camera 15401 while thelightguide 107 appears to be uniformly emitting light 15404. This isadvantageous to conceal the camera 15401 within the film-basedlightguide 107 shape where the light emitting device 15400 isfunctioning as a “one-way” light fixture analogous to a one way mirror.In another embodiment, the light extraction features 15405 are printedwhite ink dots that are over printed with light absorbing ink such thatlight scattered by and through the light extraction features 15405 isabsorbed and less scattered light directly enters the entrance apertureof the camera 15401 and creates noise and reduces the image contrast.The camera 15401 may be rotatable, fixed, infrared or visible camera andmore than one camera may be disposed on the side of the film-basedlightguide 107 opposite the light emitting surface 15406. In oneembodiment, the light emitting device 15400 is a one-way light fixtureemitting infrared light and visible light and the camera 15401 issubstantially indiscernible to a person with an acuity of 1 arcminutepositioned 3 feet from the light emitting device.

FIG. 48 is a perspective view of one embodiment of a light emittingdevice 15500 including the film-based lightguide 107 whereinsubstantially all of the light is emitted with a directional componentin the +y direction. Light 15503 from the light input coupler 101travels through the film-based lightguide 107 and is redirected by thelight extraction feature 15405 such that the light exits the lightguidetoward a first viewer 15501. The accumulation of light 15503 exiting thefilm-based lightguide 107 due to the light extraction features 15405provides an appearance of a substantially continuous light emitting areato a first viewer 15501. Light 15504 from the side of the first viewer15501 travels substantially undiffused through the film-based lightguideand can be seen by a second viewer 15502. In this embodiment, the firstviewer 15501 sees a substantially continuous light emitting surface andthe second viewer can see through the film-based lightguide 107 and seethe first viewer 15501 without the first viewer 15501 being able to seethe second viewer 15502. In one embodiment, the one-way directionalityof the light emitted from the film-based lightguide and the lighttransmitting regions provides a “privacy light fixture.”

FIG. 49 is a cross-sectional side view of one embodiment of a light bulblight emitting device 15600 including the film-based lightguide 107 in ashape of a dome with a protective bulb 15601 covering a region of thefilm-based lightguide 107. The light emitting device 15600 includes twosets of coupling lightguides on opposite sides of a film-basedlightguide 107 that are folded underneath the film based lightguide 107and stacked adjacent each other. The film-based lightguide is formedinto a dome-like shape. Light 15606 from the light source 102 initiallytravels with a directional component in the +y direction (into the page)into a first set of coupling lightguides and a direction is changed dueto a fold in the coupling lightguides to travel with a directionalcomponent in the −x direction through the film-based lightguide 107. Thelight 15606 exits the film-based lightguide 107 after being redirectedfrom a light extraction feature 15405 disposed on the inner surface ofthe film-based lightguide 107 and passes through the protective bulb15601. Light 15605 from the light source 102 initially travels with adirectional component in the +y direction (into the page) into a secondset of coupling lightguides and a direction is changed due to the foldin the coupling lightguides to travel with a directional component inthe +x direction through the film-based lightguide 107. The light 15605exits the film-based lightguide 107 after being redirected from thelight extraction feature 15405 disposed on an inner surface of thefilm-based lightguide 107 and passes through the protective bulb 15601.The protective bulb is attached to a housing component 15607 physicallycoupled to the light emitting device 15600. The light source 102 iselectrically and thermally coupled to a circuit board 15604 which isthermally coupled to the thermal transfer element 15602. The circuitboard may include other elements such as an LED driver, controlcomponents, feedback components, communication components, and/or othersuitable elements or components known to be usable with light emittingdevices. The light emitting device 15600 receives electrical powerthrough an Edison type screw base 15603. For example, the screw typebase may be an Edison E27 for use in the United States.

FIG. 50 is a cross-sectional side view of one embodiment of a lightemitting device 15700 including the film-based lightguide 107 with asubstantially flat light emitting surface 15701 with a protective cover15703 surrounding the film-based lightguide 107. The light emittingdevice 15700 includes a film-based lightguide 107 that is foldedunderneath the light emitting surface 15701. Light 15702 from the lightsource 102 initially travels with a directional component in the +ydirection (into the page) into a first set of coupling lightguides and adirection is changed due to a fold in the coupling lightguides to travelwith a directional component in the −x direction through the film-basedlightguide 107. The light 15702 exits the film-based lightguide 107after being redirected from a light extraction feature (not shown)disposed on the side of the film-based lightguide 107 opposite the lightemitting surface and passes through the protective cover 15701. A lightreflecting film 7004 is disposed adjacent to the surface of thefilm-based lightguide 107 opposite the light emitting surface 15701 toreflect light received from the film-based lightguide 107 back throughthe film-based lightguide 107 and out of the light emitting device15700. The protective cover is attached to the housing component 15607physically coupled to the light emitting device 15700. The light source102 is electrically and thermally coupled to the circuit board 15604which is thermally coupled to the thermal transfer element 15602. Thecircuit board may include other suitable elements or components such asan LED driver, control components, feedback components, communicationcomponents, and other elements known to be usable with light emittingdevices. The light emitting device 15700 receives electrical powerthrough the Edison type screw base 15603.

FIG. 51 is a perspective view of one embodiment of a self-illuminatedpicture frame light emitting device 15800 including the light source 102and coupling lightguides 104 within a frame 15803. Light from the lightsource 102 travels through the folded coupling lightguides 104 and anon-folded coupling lightguide 9703 to reach the film-based lightguide107 including the core region 601 disposed between two cladding regions602. Light 15802 from the light source 102 travels with a directionalcomponent in the +y direction and is rotated by the fold in the couplinglightguide 104 to travel with a directional component in the +zdirection through the core region 601 of the film-based lightguide 107.When the light 15802 reaches the light extraction feature 15405 disposedadjacent (or upon) the core region 601 surface nearest the viewer 15804,the light is redirected with a component in the −y direction toward aphotograph 15801. This light 15802 illuminates the photograph 15801 andthe reflected light travels back through the film-based lightguide 107and out of the light emitting device 15800 toward the viewer 15804. Inone embodiment, the light extraction features 15405 are sufficientlysmall such that the light extraction features 15405 are at most barelyvisible to the unaided viewer. For example, in one embodiment, thelargest feature length of the light extraction features is less than oneselected from the group of: 1 millimeter, 0.5 millimeter, 0.2millimeter, 0.1 millimeter, and 0.05 millimeter. In another embodiment,the film-based lightguide in a frontlight light emitting deviceincorporated into a frame is disposed proximate or optically coupled toan inner surface of a glass sheet or window in the frame.

FIG. 52 is a perspective view of one embodiment of a light emittingdevice 15900 including light input couplers 101 and rotatable film-basedlightguides 107 physically coupled to bendable metal substrates 15901with light transmitting apertures 15903. Light 15902 from the lightinput couplers 101 is directed by coupling lightguides within the lightinput coupler 101 into the film-based lightguides 107 and directed outof the film-based lightguides 107, through the light transmittingapertures 15903 in the metal substrates 15901, and out of the lightemitting device 15900 from a light emitting surface 15904 with adirectional component in the −z direction. An angle of an output of thelight 15902 may be adjusted by rotating the substrate 15901 andfilm-based lightguide 107 combinations by bending. In this embodiment, ashape of the film-based lightguides 107 and bendable substrates 15901are substantially trapezoidal. Other suitable shapes may be usedincluding circular shapes, semicircular, rectangular, square, arcuate,wave-like, polygonal, and/or other shapes. In another embodiment, thelight input couplers 101 are rotatable along with the film-basedlightguides 107 and substrates 15901. In another embodiment, thesubstrate 15901 is disposed on the side of the film-based lightguide 107opposite the light emitting surface 15904 and the substrate issubstantially opaque, such as a thin sheet of aluminum. In a furtherembodiment, the light emits from the film-based lightguide 107 and lightemitting device 15900 with directional components in the +z and −zdirection such the light emitting device 15900 has uplight and downlightlight emitting profiles.

FIG. 53 is a perspective view of a light emitting device 16000 includingthe light input coupler 101, the film-based lightguide 107, and areceiver which may include a sensor 16005 configured in signalcommunication to receive signals, such as radio frequency communicationsignals 16003 or visual information 16002 from an electronic device16006 or a person 16004. In one embodiment, the receiver 16005 includesa radio frequency transceiver disposed to receive and transmit the radiofrequency communication signals 16003 to the electronic device 16006. Inanother embodiment, the receiver 16005 includes a camera disposed toreceive the visual information 16002 (such as images and recognizablefeatures) from the person 16004. In a further embodiment, the lightemitting device 16000 changes a property of the light output (such asaverage luminance, color, and/or which film-based lightguide layer isilluminated, for example) based on information derived from the radiofrequency communication signals 16003 or the visual information 16002derived from the electronic device 16006 or the person 16004.

FIG. 54 is a perspective view of a light emitting device 16100 includingthe light input coupler 101, and the film-based lightguide 107 extendinginto a point of purchase display 16104 displaying products 1710. Thelight input coupler 101 is disposed above a support structure orsurface, such as above a plane of a ceiling 16103 and in certainembodiments is not visible. The film-based lightguide 107 receives light16102 in the light input coupler 101 and transmits the light in awaveguide condition into the point of purchase display base 16104 wherethe light is emitted in a form of light emitting indicia 16101. Thefilm-based lightguide 107 is substantially transparent in a regionbetween the point of purchase display base 16104 and a plane of theceiling 16103 such that the film-based lightguide 107 does not obscure aview of other areas of the room. By placing the light input coupler 101above the plane of the ceiling 16103, an electrical power cable 1003 ishidden from view and the point of purchase display base 16104 does notneed to have a power cable extending from it. This can increase theflexibility of locating the point of purchase display at variouslocations where running power cables would be undesirable.

FIG. 55 is a perspective view of a light emitting device 16200functioning as a display including the light input coupler 101, thefilm-based lightguide 107, and the receiver 16005 disposed to receivethe radio frequency communication signals 16003 from an electronicdevice 16204, a wireless thermometer 16202, or a personal health monitor16203 (such as a heart rate monitor). In one embodiment, the receiver16005 includes a radio frequency transceiver disposed to receive andtransmit the radio frequency communication signals 16003 to a devicelocated nearby or directly or indirectly through a wireless network. Thelight emitting device 16200 may provide information by emitting light16201 from one or more regions that represent information withoutreadable icons or characters. For example, the light emitting device16200 may include a frontlight device on or within a light emittingframe around a picture of an individual that emits green light 16201toward a mat board of the frame if the individual's heart rateinformation transmitted by a personal health monitor 16203 is within afirst predetermined zone and the mat board becomes red if the heart rateis outside of the first predetermined zone to alert the viewer.Similarly, the light emitting device 16200 may be coupled to a lightemitting clock face that is green if the GPS coordinates from anindividual's electronic device 16204 (such as a cellphone) are within apredetermined zone and the clock face flashes red in color if theelectronic device is located outside the predetermined zone which couldindicate that a child has left a safe area, for example. In anotherembodiment, the light emitting device 16200 is disposed on the frame ofa computer monitor and emits blue light if the temperature measured by awireless thermometer 16202 located outside is below a predeterminedlevel and emits red light if the temperature is above the predeterminedlevel. In one embodiment, the light emitting device 16200 changes aproperty of the light output (such as intensity, color, and/or whichfilm-based lightguide layer is illuminated, for example) based oninformation derived by the radio frequency communication signals 16003from the electronic device 16204 or by a wired connection to theelectronic device 16204 directly or across a network.

FIG. 56 is a perspective view of a light emitting device 16300incorporated into a flexible packaging 16301 including the light inputcoupler 101 and the film-based lightguide 107. Light 16302 from thelight input coupler 101 travels through the film-based lightguide 107and is emitted from the film-based lightguide 107 and the packaging16301 in a form of indicia 16303, for example.

In one embodiment, a device includes a film-based lightguide and a filmadjustment mechanism configurable to adjust an orientation of a regionof the film-based lightguide such that an angular light output profilefrom the device changes when a light source emits light that travels ina waveguide condition through the film-based lightguide. The filmadjustment mechanism is configurable to adjust a radius of curvature ofthe region of the film-based lightguide. The film adjustment mechanismis electronically adjustable in certain embodiments. In one embodiment,the film adjustment mechanism includes at least one drawstringconfigurable to change the angular light output profile. In anotherembodiment, the film adjustment mechanism includes a plasticallydeformable element deformable to adjust the orientation of the region ofthe film-based lightguide. The film adjustment mechanism is configurableto adjust the position of the region of the film-based lightguide. Thedevice includes a light source configured to emit light that enters thefilm-based lightguide, wherein the film adjustment mechanism isconfigurable to adjust the orientation of the region of the film-basedlightguide relative to the light source. In one embodiment, the deviceis a light fixture. In certain embodiments, the orientation of theregion of the film-based lightguide is adjustable to change an angle ofa peak luminous intensity of the angular light output profile. Incertain embodiments, the orientation of the region of the film-basedlightguide in a light output plane is adjustable to change an angularfull-width at half maximum luminous intensity of the angular lightoutput profile in the light output plane. In certain embodiments, thelight angular light output profile has an angular full-width at halfmaximum luminous intensity in a light output plane less than 120degrees. In one embodiment, the device includes an array of couplinglightguides extending from the film-based lightguide, and the array ofcoupling lightguides are folded and positioned to receive light emittedfrom the light source.

In one embodiment, a light emitting device has an adjustable angularlight output profile. The light emitting device includes a light sourceand a film-based lightguide configured to receive light emitted from thelight source. The film-based lightguide includes a light emitting regionat least partially defined by a group of light extraction features. Thelight emitting region has a first radius of curvature, wherein the firstradius of curvature of the light emitting region is adjustable to asecond radius of curvature to change the angular light output profile ofthe light emitted from the light emitting device. The light emittingdevice may also include a film adjustment mechanism configurable toadjust the first radius of curvature of the light emitting region. Inone embodiment, the film-based lightguide includes a substantiallynon-light emitting region defined in an optical path of light from thelight source between the light source and the light emitting region. Incertain embodiments, a curvature of the film-based lightguide in thelight emitting region is different from a curvature of the film-basedlightguide in the substantially non-light emitting region. In certainembodiments, the light emitting device is a point of purchase displaythat includes a base and the light source is positioned proximate aceiling. The film-based lightguide may include a curved surface in alight output plane and the light emitting region may include aninflection point of the curved surface. In certain embodiments, thefirst radius of curvature of the light emitting region is adjustable tochange an angle of a peak luminous intensity of the angular light outputprofile. In certain embodiments, the first radius of curvature of thelight emitting region in a light output plane is adjustable to change anangular full-width at half maximum luminous intensity of the angularlight output profile in a light output plane. The light emitting devicemay further include a low contact area cover having surface relieffeatures.

In one embodiment, a method of changing an angular light output profileof a light emitting device includes changing an orientation of a lightemitting region of a film-based lightguide configured to receive lightemitted from a light source through an array of coupling lightguides tochange the angular light output profile of the light emitting device.Changing an orientation of the light emitting region may includechanging a radius of curvature of the light emitting region. Changing anorientation of the light emitting region may include adjusting a filmadjustment mechanism physically coupled to the film-based lightguide.

Examples

Embodiments are illustrated in the following example(s). The followingexamples are given for the purpose of illustration, but not for limitingthe scope or spirit of the invention.

In one embodiment, coupling lightguides are formed by cutting strips atone or more ends of a film which forms coupling lightguides (strips) anda lightguide region (remainder of the film). On the free end of thestrips, the strips are bundled together into an arrangement much thickerthan the thickness of the film itself. On the other end, the stripsremain physically and optically attached and aligned to the larger filmlightguide. The film cutting is achieved by stamping, laser-cutting,mechanical cutting, water-jet cutting, local melting or other filmprocessing methods. In one embodiment, the cut results in an opticallysmooth surface to promote total internal reflection of the light toimprove light guiding through the length of the strips. A light sourceis coupled to the bundled strips. The strips are arranged so that lighttravels through the strips via total internal reflection and istransferred into the film lightguide portion. The bundle input of thestrips has a thickness much greater than the film lightguide region sothe light source can more efficiently transfer light into the lightguidecompared to trying to couple to the edge or top of the film. The stripscan be melted or mechanically forced together at the input to improvecoupling efficiency. If the bundle is square shaped, a length of one ofits sides I, is given by I˜√(w×t) where w is a total width of thelightguide input edge and t is a thickness of the film. For example, a0.1 mm thick film with 1 meter (m) edge would give a square input bundlewith dimensions of 1 cm×1 cm. Considering these dimensions, the bundleis much easier to couple light into compared to coupling along thelength of the film when using typical light sources (e.g. incandescent,fluorescent; metal halide, xenon and LED sources).

An example of one embodiment that can be brought to practice is givenhere. The assembly starts with 0.25 mm thick polycarbonate film that is40 cm wide and 100 cm long. A cladding layer of a lower refractive indexmaterial of approximately 0.01 mm thickness is disposed on a top surfaceand a bottom surface of the film. The cladding layer can be added bycoating or co-extruding a material with lower refractive index onto thefilm core. One edge of the film is mechanically cut into 40 strips of 1cm width using a sharp cutting tool, such as a razor blade. The edges ofthe slots are then exposed to heat to improve the smoothness for opticaltransfer. The slots are combined into a bundle of approximately 1 cm×1cm cross-section. To the end of the bundle a number of different typesof light sources can be coupled (e.g. xenon, metal halide, incandescent,LED or Laser). Light travels through the bundle into the film and out ofthe image area. Light may be extracted from the film lightguide by laseretching into the film, which adds a surface roughness that results infrustrated total internal reflectance. Multiple layers of film can becombined to make multi-color or dynamic signs. The shape of thefilm-based lightguide, the shape of the light emitting region, theorientation of the light emitting region, and/or the position of thelight emitting region can be adjusted to change the angular output ofthe light emitting device.

An example of one embodiment that has been brought to practice isdescribed here. The apparatus began with a 15 mil thick polycarbonatefilm which was 18 inches wide and 30 inches long. The 18 inch edge ofthe film is cut into 0.25 inch wide strips using an array of razorblades. These strips are grouped into three six inch wide sets ofstrips, which are further split into two equal sets that were foldedtowards each other and stacked separately into 0.165 inch by 0.25 inchstacks. Each of the three pairs of stacks was then combined together inthe center to create a combined and singular input stack of 0.33 inch by0.25 inch size. An LED module, MCE LED module from Cree Inc., is coupledinto each of the three input stacks. Light emitted from the LED entersthe film stack with an even input, and a portion of this light remainswithin each of the 15 mil strips via total internal reflections whilepropagating through the strip. The light continues to travel down eachstrip as they break apart in their separate configurations, beforeentering the larger lightguide. Furthermore, a finned aluminum heat sinkwas placed down the length of each of the three coupling apparatuses todissipate heat from the LED. This assembly shows a compact design thatcan be aligned in a linear array, to create uniform light. The shape ofthe film-based lightguide, the shape of the light emitting region, theorientation of the light emitting region, or the position of the lightemitting region can be adjusted to change the angular output of thelight emitting device.

Exemplary embodiments of light emitting devices and methods for makingor producing the same are described above in detail. The devices,components, and methods are not limited to the specific embodimentsdescribed herein, but rather, the devices, components of the devicesand/or steps of the methods may be utilized independently and separatelyfrom other devices, components and/or steps described herein. Further,the described devices, components and/or the described methods steps canalso be defined in, or used in combination with, other devices and/ormethods, and are not limited to practice with only the devices andmethods as described herein.

While the disclosure includes various specific embodiments, thoseskilled in the art will recognize that the embodiments can be practicedwith modification within the spirit and scope of the disclosure and theclaims.

EQUIVALENTS

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, numerous equivalents to thespecific procedures described herein. Such equivalents are considered tobe within the scope of the invention. Various substitutions,alterations, and modifications may be made to the invention withoutdeparting from the spirit and scope of the invention. Other aspects,advantages, and modifications are within the scope of the invention.This application is intended to cover any adaptations or variations ofthe specific embodiments discussed herein. Unless otherwise indicated,all numbers expressing feature sizes, amounts, and physical propertiesused in the specification and claims are to be understood as beingmodified by the term “about”. Accordingly, unless indicated to thecontrary, the numerical parameters set forth in the foregoingspecification and attached claims are approximations that can varydepending upon the desired properties sought to be obtained by thoseskilled in the art utilizing the teachings disclosed herein. Unlessindicated to the contrary, all tests and properties are measured at anambient temperature of 25 degrees Celsius or the environmentaltemperature within or near the device when powered on (when indicated)under constant ambient room temperature of 25 degrees Celsius.

What is claimed is:
 1. A light emitting device comprising: a lightguideformed from a film comprising a core layer, the film having a thicknessless than 0.5 millimeters; a plurality of strips of the film extendedfrom a lightguide region of the film, each strip of the plurality of thestrips is folded and stacked such that the strips of the plurality ofstrips are parallel to each other and ends of the strips of theplurality of strips define a light input surface; light extractionfeatures formed within the lightguide region of the film, the lightextraction features defining a light emitting region of the film; and atleast one light source positioned to emit light into the light inputsurface, the light from the at least one light source passes through thelight input surface, propagates through the strips of the plurality ofstrips and the lightguide region by total internal reflection within thecore layer, and is directed by the light extraction features to exit thelightguide region of the film in the light emitting region, wherein thecore layer is a layer of glass.
 2. The light emitting device of claim 1wherein the film comprises a cladding layer optically coupled to thecore layer.
 3. The light emitting device of claim 2 wherein the claddinglayer has a glass transition temperature less than the core layer. 4.The light emitting device of claim 2 wherein the cladding layer is anadhesive.
 5. The light emitting device of claim 1 wherein a largestdimension of the light emitting region in a plane comprising the lightemitting region divided by an average thickness of the core layer in thelight emitting region is greater than
 500. 6. The light emitting deviceof claim 1 wherein a largest dimension of the light emitting region in aplane comprising the light emitting region divided by an averagethickness of the core layer in the light emitting region is greater than1000.
 7. The light emitting device of claim 1 wherein a largestdimension of the light emitting region in a plane comprising the lightemitting region divided by an average thickness of the core layer in thelight emitting region is greater than 10,000.
 8. The light emittingdevice of claim 1 wherein the thickness of the film is less than 0.2millimeters.
 9. The light emitting device of claim 8 wherein a largestdimension of the light emitting region in a plane comprising the lightemitting region divided by an average thickness of the core layer in thelight emitting region is greater than
 500. 10. The light emitting deviceof claim 1 wherein the at least one light source has a peak wavelengthwithin a range of 350 nanometers to 400 nanometers.
 11. The lightemitting device of claim 1 wherein the at least one light source has apeak wavelength within a range of 800 nanometers to 1200 nanometers. 12.The light emitting device of claim 1 wherein the glass is a borosilicateglass.
 13. The light emitting device of claim 1 wherein the glass is analuminoborosilicate glass.
 14. The light emitting device of claim 1wherein the glass layer comprises an edge, and the lightguide comprisesa coating of an organic material applied to the edge of the layer ofglass.
 15. A device comprising: a light input coupler comprising apolymer film comprising a plurality of strips of the polymer filmextended from a lightguide region of the polymer film, each strip of theplurality of the strips is folded and stacked such that the plurality ofstrips define a light input surface, and at least one light sourcepositioned to emit light into the light input surface; a lightguideformed from a film comprising a glass core layer, the glass core layerhaving a thickness less than 0.5 millimeters; light extraction featuresformed within a lightguide region of the film comprising the glass corelayer, the light extraction features defining a light emitting region ofthe film; wherein the lightguide region of the polymer film is opticallycoupled to the lightguide region of the film comprising the glass corelayer.
 16. The light emitting device of claim 15 wherein the polymerfilm comprises silicone.
 17. The light emitting device of claim 15wherein the thickness of the core layer is less than 0.2 millimeters anda largest dimension of the light emitting region in a plane comprisingthe light emitting region divided by an average thickness of the corelayer in the light emitting region is greater than
 500. 18. The lightemitting device of claim 15 wherein the glass core layer comprises anedge, and the lightguide comprises a coating of an organic materialapplied to the edge of the glass core layer.
 19. The light emittingdevice of claim 15 wherein the at least one light source has a peakwavelength within a range of 800 nanometers to 1200 nanometers.
 20. Alight emitting device comprising: a lightguide formed from a filmcomprising a glass core layer, the core layer having a thickness lessthan 0.5 millimeters; a plurality of polymer strips optically coupled tothe glass core layer, each strip of the plurality of polymer strips isfolded and stacked such that the plurality of strips define a lightinput surface; light extraction features formed within the lightguideregion of the film, the light extraction features defining a lightemitting region of the film; and at least one light source positioned toemit light into the light input surface, the light from the at least onelight source passes through the light input surface, propagates throughthe plurality of polymer strips and the lightguide region by totalinternal reflection within the glass core layer, and is directed by thelight extraction features to exit the lightguide region of the film inthe light emitting region.